DIY: Clean your Throttle Bodies
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Joined: Mar 2008
Posts: 38
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From: Pearl City, HI.
I read back and saw the accelerator pedal and throttle valve positioning learnings, I really think I am going to do this, my car has been acting really weird and I did have my ECM replaced recently, I have a weird idle, and really inconsistent issues with throttle response and acceleration through gears
Registered User
Joined: Mar 2008
Posts: 38
Likes: 0
From: Pearl City, HI.
but no
w the car runs so much better and pulls harder. also my instant MPG can go higher than 25 MPG while on the freeway before it'll be around 20. much more smoother gear changing and low end pull without a struggling feel.
w the car runs so much better and pulls harder. also my instant MPG can go higher than 25 MPG while on the freeway before it'll be around 20. much more smoother gear changing and low end pull without a struggling feel.
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Joined: Aug 2011
Posts: 108
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Just because I have seen so many people asking details on the procedures you MUST perform:
ACCELERATOR PEDAL RELEASED POSITION LEARNING
THROTTLE VALVE CLOSED POSITION LEARNING
THEN you can perform
IDLE AIR VOLUME LEARNING
If you dont follow the instructions it will not be properly reset. Here are the details straight from the service manual.
ACCELERATOR PEDAL RELEASED POSITION LEARNING
ACCELERATOR PEDAL RELEASED POSITION LEARNING : Description INFOID:0000000005624633
Accelerator Pedal Released Position Learning is a function of ECM to learn the fully released position of the
accelerator pedal by monitoring the accelerator pedal position sensor output signal. It must be performed each
time the harness connector of the accelerator pedal position sensor or ECM is disconnected.
ACCELERATOR PEDAL RELEASED POSITION LEARNING : Special Repair Requirement INFOID:0000000005624634
1.START
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.
THROTTLE VALVE CLOSED POSITION LEARNING
THROTTLE VALVE CLOSED POSITION LEARNING : Description INFOID:0000000005624635
Throttle Valve Closed Position Learning is a function of ECM to learn the fully closed position of the throttle
valve by monitoring the throttle position sensor output signal. It must be performed each time harness connector of electric throttle control actuator or ECM is disconnected.
THROTTLE VALVE CLOSED POSITION LEARNING : Special Repair Requirement
INFOID:0000000005624636
1.START
1. Make sure that accelerator pedal is fully released.
Revision: 2009 November 2010 G37 SedanEC-20
< BASIC INSPECTION > [VQ37VHR]
INSPECTION AND ADJUSTMENT
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
IDLE AIR VOLUME LEARNING
IDLE AIR VOLUME LEARNING : Description INFOID:0000000005624637
Idle Air Volume Learning is a function of ECM to learn the idle air volume that keeps engine idle speed within
the specific range. It must be performed under the following conditions:
• Each time electric throttle control actuator or ECM is replaced.
• Each time VVEL actuator sub assembly or VVEL control module is replaced.
• Idle speed or ignition timing is out of specification.
IDLE AIR VOLUME LEARNING : Special Repair Requirement INFOID:0000000005624638
PRECONDITIONING
Make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.
• Battery voltage: More than 12.9 V (At idle)
• Engine coolant temperature: 70 - 105°C (158 - 221°F)
• PNP switch: ON (M/T models)
• Selector lever: P or N (A/T models)
• Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, if the parking brake is applied before the engine is
started the headlamp will not be illuminated.
• Steering wheel: Neutral (Straight-ahead position)
• Vehicle speed: Stopped
• Transmission: Warmed-up
- A/T models
• With CONSULT-III: Drive vehicle until “ATF TEMP SE 1” in “DATA MONITOR” mode of “A/T” system indicates less than 0.9 V.
• Without CONSULT-III: Drive vehicle for 10 minutes.
- M/T models
• Drive vehicle for 10 minutes.
TO PERFORM IDLE AIR VOLUME LEARNING
NOTE:
• It is better to count the time accurately with a clock.
Revision: 2009 November 2010 G37 SedanINSPECTION AND ADJUSTMENT
• It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit has
a malfunction.
1. Perform Accelerator Pedal Released Position Learning. Refer to EC-19, "ACCELERATOR PEDAL
RELEASED POSITION LEARNING : Special Repair Requirement".
2. Perform Throttle Valve Closed Position Learning. EC-19, "THROTTLE VALVE CLOSED POSITION
LEARNING : Special Repair Requirement".
3. Start engine and warm it up to normal operating temperature.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
6. Repeat the following procedure quickly five times within 5 seconds.
- Fully depress the accelerator pedal.
- Fully release the accelerator pedal.
7. Wait 7 seconds, fully depress the accelerator pedal for approx. 20 seconds until the MIL stops blinking
and illuminates.
8. Fully release the accelerator pedal within 3 seconds after the MIL illuminates.
9. Start engine and let it idle.
10. Wait 20 seconds.
ACCELERATOR PEDAL RELEASED POSITION LEARNING
THROTTLE VALVE CLOSED POSITION LEARNING
THEN you can perform
IDLE AIR VOLUME LEARNING
If you dont follow the instructions it will not be properly reset. Here are the details straight from the service manual.
ACCELERATOR PEDAL RELEASED POSITION LEARNING
ACCELERATOR PEDAL RELEASED POSITION LEARNING : Description INFOID:0000000005624633
Accelerator Pedal Released Position Learning is a function of ECM to learn the fully released position of the
accelerator pedal by monitoring the accelerator pedal position sensor output signal. It must be performed each
time the harness connector of the accelerator pedal position sensor or ECM is disconnected.
ACCELERATOR PEDAL RELEASED POSITION LEARNING : Special Repair Requirement INFOID:0000000005624634
1.START
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.
THROTTLE VALVE CLOSED POSITION LEARNING
THROTTLE VALVE CLOSED POSITION LEARNING : Description INFOID:0000000005624635
Throttle Valve Closed Position Learning is a function of ECM to learn the fully closed position of the throttle
valve by monitoring the throttle position sensor output signal. It must be performed each time harness connector of electric throttle control actuator or ECM is disconnected.
THROTTLE VALVE CLOSED POSITION LEARNING : Special Repair Requirement
INFOID:0000000005624636
1.START
1. Make sure that accelerator pedal is fully released.
Revision: 2009 November 2010 G37 SedanEC-20
< BASIC INSPECTION > [VQ37VHR]
INSPECTION AND ADJUSTMENT
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
IDLE AIR VOLUME LEARNING
IDLE AIR VOLUME LEARNING : Description INFOID:0000000005624637
Idle Air Volume Learning is a function of ECM to learn the idle air volume that keeps engine idle speed within
the specific range. It must be performed under the following conditions:
• Each time electric throttle control actuator or ECM is replaced.
• Each time VVEL actuator sub assembly or VVEL control module is replaced.
• Idle speed or ignition timing is out of specification.
IDLE AIR VOLUME LEARNING : Special Repair Requirement INFOID:0000000005624638
PRECONDITIONING
Make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.
• Battery voltage: More than 12.9 V (At idle)
• Engine coolant temperature: 70 - 105°C (158 - 221°F)
• PNP switch: ON (M/T models)
• Selector lever: P or N (A/T models)
• Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, if the parking brake is applied before the engine is
started the headlamp will not be illuminated.
• Steering wheel: Neutral (Straight-ahead position)
• Vehicle speed: Stopped
• Transmission: Warmed-up
- A/T models
• With CONSULT-III: Drive vehicle until “ATF TEMP SE 1” in “DATA MONITOR” mode of “A/T” system indicates less than 0.9 V.
• Without CONSULT-III: Drive vehicle for 10 minutes.
- M/T models
• Drive vehicle for 10 minutes.
TO PERFORM IDLE AIR VOLUME LEARNING
NOTE:
• It is better to count the time accurately with a clock.
Revision: 2009 November 2010 G37 SedanINSPECTION AND ADJUSTMENT
• It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit has
a malfunction.
1. Perform Accelerator Pedal Released Position Learning. Refer to EC-19, "ACCELERATOR PEDAL
RELEASED POSITION LEARNING : Special Repair Requirement".
2. Perform Throttle Valve Closed Position Learning. EC-19, "THROTTLE VALVE CLOSED POSITION
LEARNING : Special Repair Requirement".
3. Start engine and warm it up to normal operating temperature.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
6. Repeat the following procedure quickly five times within 5 seconds.
- Fully depress the accelerator pedal.
- Fully release the accelerator pedal.
7. Wait 7 seconds, fully depress the accelerator pedal for approx. 20 seconds until the MIL stops blinking
and illuminates.
8. Fully release the accelerator pedal within 3 seconds after the MIL illuminates.
9. Start engine and let it idle.
10. Wait 20 seconds.
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Joined: Jul 2010
Posts: 246
Likes: 2
I've read this now a couple times to get the process down, I have a couple questions:
Does this work for every model G37 I have a 2009 G37x coupe will it apply for me?
What is Consult-III? I use Uprev as a tuner, I can monitor the coolant temp and I believe battery voltage using Uprev, should I hook up my Uprev while performing these steps?
I just had my ECM replaced two weeks earlier the dealership replaced my computer with a computer that was not the correct software. using Uprev, I was able to have the correct software flashed to the new ECM. do you think the Dealership would perform these learning procedure steps after disconnecting my ECM, like I mentioned they installed a ECM for a car with ICC yet I don't have that, so I diagnosed the problem myself and fixed it.
Why doesn't the throttle closed position learning process work everytime you turn the ignition off, what makes this one time you perform it different? Is it that you have do it in succession with the other procedures? and how do I confirm the closing of the throttle valve, what sound am I supposed to be listening for?
Does this work for every model G37 I have a 2009 G37x coupe will it apply for me?
What is Consult-III? I use Uprev as a tuner, I can monitor the coolant temp and I believe battery voltage using Uprev, should I hook up my Uprev while performing these steps?
I just had my ECM replaced two weeks earlier the dealership replaced my computer with a computer that was not the correct software. using Uprev, I was able to have the correct software flashed to the new ECM. do you think the Dealership would perform these learning procedure steps after disconnecting my ECM, like I mentioned they installed a ECM for a car with ICC yet I don't have that, so I diagnosed the problem myself and fixed it.
Why doesn't the throttle closed position learning process work everytime you turn the ignition off, what makes this one time you perform it different? Is it that you have do it in succession with the other procedures? and how do I confirm the closing of the throttle valve, what sound am I supposed to be listening for?
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Joined: Aug 2011
Posts: 108
Likes: 1
Yes it should since the engines are the same with no technical differences.
Consult III is Nissans diagnostic tool. NO do not hook up your uprev. Uprev is its own software and performing any on-board diagnostics while hooking up to a non-certified nissan diagnostics tool could potentially damage one or the other.
Interesting that they did this but keep in mind ECU maybe newer and have slightly different defaults. It probably doesnt have any harm having the ICC... Your lucky that new flash didnt cause issues with the new ECU... but generally means they are adding to the ECU and not subtracting or changing other parameters.
Regarding performing these action, they are not necessary as they are automatically set at the factory. When a new car is preped at the factory, they use diagnostic tools to set the car up with the proper specs. This method its meant for in the field diagnostics and remediation of minor issues OR when a change impacts said components. These reset set them based on the current altered conditions. Generally you dont need to perform this unless you mess with anything on the upper intake. I would question the need if you mess with anything on the lower or exhaust it cant hurt though (unless you do it wrong).
Regarding the throttle position, good question but I suspect they dont want it to have that much devision for every time you start your car. The method above ensures that it is set once and only once UNLESS you force a reset. I have heard many say that over time it goes out of spec and performing this helps acceleration. I think its a placebo.
Yes... follow the directions exactly. Especially read pre-conditions.
Its hard to say, but you typically will have to visually inspect the throttle valve to know for sure... Keep in mind if it was stuck open your idle would be off pretty severly. You would also need something binding... So just a few full presses should get it to its closed state. You can also typically hear it if you have someone push the accelerator... When it closes its like metal hitting metal...
Consult III is Nissans diagnostic tool. NO do not hook up your uprev. Uprev is its own software and performing any on-board diagnostics while hooking up to a non-certified nissan diagnostics tool could potentially damage one or the other.
Interesting that they did this but keep in mind ECU maybe newer and have slightly different defaults. It probably doesnt have any harm having the ICC... Your lucky that new flash didnt cause issues with the new ECU... but generally means they are adding to the ECU and not subtracting or changing other parameters.
Regarding performing these action, they are not necessary as they are automatically set at the factory. When a new car is preped at the factory, they use diagnostic tools to set the car up with the proper specs. This method its meant for in the field diagnostics and remediation of minor issues OR when a change impacts said components. These reset set them based on the current altered conditions. Generally you dont need to perform this unless you mess with anything on the upper intake. I would question the need if you mess with anything on the lower or exhaust it cant hurt though (unless you do it wrong).
Regarding the throttle position, good question but I suspect they dont want it to have that much devision for every time you start your car. The method above ensures that it is set once and only once UNLESS you force a reset. I have heard many say that over time it goes out of spec and performing this helps acceleration. I think its a placebo.
Yes... follow the directions exactly. Especially read pre-conditions.
Its hard to say, but you typically will have to visually inspect the throttle valve to know for sure... Keep in mind if it was stuck open your idle would be off pretty severly. You would also need something binding... So just a few full presses should get it to its closed state. You can also typically hear it if you have someone push the accelerator... When it closes its like metal hitting metal...
I've read this now a couple times to get the process down, I have a couple questions:
Does this work for every model G37 I have a 2009 G37x coupe will it apply for me?
What is Consult-III? I use Uprev as a tuner, I can monitor the coolant temp and I believe battery voltage using Uprev, should I hook up my Uprev while performing these steps?
I just had my ECM replaced two weeks earlier the dealership replaced my computer with a computer that was not the correct software. using Uprev, I was able to have the correct software flashed to the new ECM. do you think the Dealership would perform these learning procedure steps after disconnecting my ECM, like I mentioned they installed a ECM for a car with ICC yet I don't have that, so I diagnosed the problem myself and fixed it.
Why doesn't the throttle closed position learning process work everytime you turn the ignition off, what makes this one time you perform it different? Is it that you have do it in succession with the other procedures? and how do I confirm the closing of the throttle valve, what sound am I supposed to be listening for?
Does this work for every model G37 I have a 2009 G37x coupe will it apply for me?
What is Consult-III? I use Uprev as a tuner, I can monitor the coolant temp and I believe battery voltage using Uprev, should I hook up my Uprev while performing these steps?
I just had my ECM replaced two weeks earlier the dealership replaced my computer with a computer that was not the correct software. using Uprev, I was able to have the correct software flashed to the new ECM. do you think the Dealership would perform these learning procedure steps after disconnecting my ECM, like I mentioned they installed a ECM for a car with ICC yet I don't have that, so I diagnosed the problem myself and fixed it.
Why doesn't the throttle closed position learning process work everytime you turn the ignition off, what makes this one time you perform it different? Is it that you have do it in succession with the other procedures? and how do I confirm the closing of the throttle valve, what sound am I supposed to be listening for?
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Joined: Jul 2010
Posts: 246
Likes: 2
https://www.myg37.com/forums/g37-cou...t-working.html
Mike Please check this thread out it's about my ECM situation
I am going to give this process a try I am working with Uprev because I think there is big issues with how my car is tuned I have a Stillen Long Tube CAI, test pipes, and a y-pipe I am noticing major inconsistencies
Mike Please check this thread out it's about my ECM situation
I am going to give this process a try I am working with Uprev because I think there is big issues with how my car is tuned I have a Stillen Long Tube CAI, test pipes, and a y-pipe I am noticing major inconsistencies
Registered User
Joined: Aug 2011
Posts: 108
Likes: 1
Whats funny is until I got to the bottom of that thread I had it figured out... then saw that they gave you a ECM with ICC which you didnt have... Ha ha...
Anyway... Yes this process may fix your issue - if it does not then you need to have the Mixture Self Learning value reset. Unfortunately you need either the a GST or CONSULT-III or some other device that allows you to reset those values.
Some think by resetting the ECU (various methods out there) it resets all values in the the ECU but it doesnt - it only resets the DTC codes - at least this is what the service manual states.
You want to go completely reset... disconnect the batter for 24 hours... then perform the throttle, Idle, etc. routines if necessary.. this guarantees a complete reset.
Anyway... Yes this process may fix your issue - if it does not then you need to have the Mixture Self Learning value reset. Unfortunately you need either the a GST or CONSULT-III or some other device that allows you to reset those values.
Some think by resetting the ECU (various methods out there) it resets all values in the the ECU but it doesnt - it only resets the DTC codes - at least this is what the service manual states.
You want to go completely reset... disconnect the batter for 24 hours... then perform the throttle, Idle, etc. routines if necessary.. this guarantees a complete reset.
https://www.myg37.com/forums/g37-cou...t-working.html
Mike Please check this thread out it's about my ECM situation
I am going to give this process a try I am working with Uprev because I think there is big issues with how my car is tuned I have a Stillen Long Tube CAI, test pipes, and a y-pipe I am noticing major inconsistencies
Mike Please check this thread out it's about my ECM situation
I am going to give this process a try I am working with Uprev because I think there is big issues with how my car is tuned I have a Stillen Long Tube CAI, test pipes, and a y-pipe I am noticing major inconsistencies
Registered User
Joined: Jul 2010
Posts: 246
Likes: 2
I think I am going to do this over the weekend, I am waiting on Uprev to send me a new re-flash, I am almost certain that I have some kind of tuning/positioning/learning issue with my car, I replaced the cats with Test pipes and slapped on a y-pipe, I know those are small bolt ons but I think all the mods have definitely caused my car to start acting up
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Joined: Aug 2011
Posts: 108
Likes: 1
So what do you mean by acting up? What are the symptoms?
I think I am going to do this over the weekend, I am waiting on Uprev to send me a new re-flash, I am almost certain that I have some kind of tuning/positioning/learning issue with my car, I replaced the cats with Test pipes and slapped on a y-pipe, I know those are small bolt ons but I think all the mods have definitely caused my car to start acting up
Registered User
Joined: Jul 2010
Posts: 246
Likes: 2
lol it's hard to explain, I was trying to explain it to the guy at uprev through email and that probably got absolutely no where, and I'm sure no one will really understand what I am talking about until you drive it you know. But, from jumping in a 2011 G37 sedan loaner to mine is like night an day, using manual mode in the loaner very crisp, responsive, and even. When getting back in my car, I just feel like I have lost every bit of consistency, not crisp not responsive, very doggy/laggy in acceleration and throttle response, my car just feels like a pig, with the couple bolt-ons that I have I feel it should improve the performance not bog the car down you know.
An example is if I am in 4th gear then someone in front of me is turning, i will brake and downshift into second, rolling at about 10-15 mph, and then try to accelerate out of second gear and there is no responsiveness and no acceleration it takes a second to hesitate and then finally starts to accelerate, and while accelerating through that gear there is a lot of choppiness and chugging, I have an Automatic.
An example is if I am in 4th gear then someone in front of me is turning, i will brake and downshift into second, rolling at about 10-15 mph, and then try to accelerate out of second gear and there is no responsiveness and no acceleration it takes a second to hesitate and then finally starts to accelerate, and while accelerating through that gear there is a lot of choppiness and chugging, I have an Automatic.
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Joined: Aug 2011
Posts: 108
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Well... Definitely try the above resets - some have complained of that doggy like feeling and has restored it...
BUT... the delay you feel is the tranny and not the engine... I have the same issue and so does everyone else. There are MANY MANY threads complaining of the 3 to 2 shift or 4 to 3 shift... It doesnt always happen but more often then you would like... I have been experimenting with turning off traction control - no results yet but seems to be less.. .Of course if you drive in manual or sport mode its far less apparent.
BUT... the delay you feel is the tranny and not the engine... I have the same issue and so does everyone else. There are MANY MANY threads complaining of the 3 to 2 shift or 4 to 3 shift... It doesnt always happen but more often then you would like... I have been experimenting with turning off traction control - no results yet but seems to be less.. .Of course if you drive in manual or sport mode its far less apparent.
lol it's hard to explain, I was trying to explain it to the guy at uprev through email and that probably got absolutely no where, and I'm sure no one will really understand what I am talking about until you drive it you know. But, from jumping in a 2011 G37 sedan loaner to mine is like night an day, using manual mode in the loaner very crisp, responsive, and even. When getting back in my car, I just feel like I have lost every bit of consistency, not crisp not responsive, very doggy/laggy in acceleration and throttle response, my car just feels like a pig, with the couple bolt-ons that I have I feel it should improve the performance not bog the car down you know.
An example is if I am in 4th gear then someone in front of me is turning, i will brake and downshift into second, rolling at about 10-15 mph, and then try to accelerate out of second gear and there is no responsiveness and no acceleration it takes a second to hesitate and then finally starts to accelerate, and while accelerating through that gear there is a lot of choppiness and chugging, I have an Automatic.
An example is if I am in 4th gear then someone in front of me is turning, i will brake and downshift into second, rolling at about 10-15 mph, and then try to accelerate out of second gear and there is no responsiveness and no acceleration it takes a second to hesitate and then finally starts to accelerate, and while accelerating through that gear there is a lot of choppiness and chugging, I have an Automatic.
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Joined: Jul 2010
Posts: 246
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I can't remember the last time I drove in regular Automatic, I have always driven in manual mode, and it's not even the actual shift, it is just accelerating in 2nd gear or third gear where I get the awful response. Actually the only torque/acceleration is in the 1st gear. 2nd like I said, is choppy/doggy, same with third, 4th and 5th are just like dead gears and I mainly using 5,6 & 7 to sit in while I am cruising at a consistent speed
Thanks everyone for the great write up and feedbacks.
I called 2 dealers and both add TB cleaning into the 15k mile service. I thought they were just trying to make $$. From reading these posts, sounds like the TB cleaning is necessary and helps the car run better.
Infiniti of MV quotes $120 for TB cleaning, which includes resetting the idle. Time to save up, I guess.
I called 2 dealers and both add TB cleaning into the 15k mile service. I thought they were just trying to make $$. From reading these posts, sounds like the TB cleaning is necessary and helps the car run better.
Infiniti of MV quotes $120 for TB cleaning, which includes resetting the idle. Time to save up, I guess.
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Joined: Jul 2010
Posts: 246
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120 to clean the throttle bodies?!?!?!?!! what that is ridiculous it really isn't that hard, if I wasn't so **** about how I want my car to feel while I am driving it I wouldn't even bother with the idle learning procedure
