DIY: Clean your Throttle Bodies
It's maintenance that should be done just like anything else. I did it because I noticed my RPMs would drop really low and my car would shake at stop signs and red lights. It's a common sign of a dirty throttle body. Cleaning them is just preventative maintenance and it could also fix issues like shaky idling and dropping RPMs.
Today is the day that I finally have time to do this! I've read through this entire thread multiple times, but with so many different responses on the "best" way to do this, I'm trying to finalize my method before I open the hood. My goal is to obviously do this correctly and avoid having to perform unnecessary relearns. All tips/advice would be greatly appreciated!
2012 G37 Sedan Journey 31k miles
1. Unplug negative terminal or leave it connected?
2. Open butterfly or leave it alone?
3. Should I do an ECU reset even if no codes are thrown?
4. If the ECU reset is recommended, is it better to do this immediately following the cleaning of the TBs/MAF or should I drive 5-10 miles and then perform the ECU reset?
5. Can someone help me out with a link for cleaning the MAF sensor?
2012 G37 Sedan Journey 31k miles
1. Unplug negative terminal or leave it connected?
2. Open butterfly or leave it alone?
3. Should I do an ECU reset even if no codes are thrown?
4. If the ECU reset is recommended, is it better to do this immediately following the cleaning of the TBs/MAF or should I drive 5-10 miles and then perform the ECU reset?
5. Can someone help me out with a link for cleaning the MAF sensor?
If your car is still under warranty just run it by the dealer first so that you avoid the chance that you might have idle problems after cleaning. I just took it in this morning and told them that my idle dropped and engine shut off upon starting the car. (This happened to me once a few weeks ago.) When I called to make the appt the service guy said that my throttle body probably needed cleaning and that wasn't covered under warranty. They wanted $160 for the service. I decided to take it in anyways and have them take a look. They ended up replacing both throttle body under warranty at no charge to me. The service guy that helped me on site (different than the one that i talked to on the phone) told me that both throttle bodies were dirty and built up a tar like substance and that they just decided to replace them. I have about 45K on it. Car is completely stock at the moment. (I have the K&N intake system in my garage ready to install)
So it doesn't hurt to run it by the dealer to see if they will do something about it if you are still under warranty.
So it doesn't hurt to run it by the dealer to see if they will do something about it if you are still under warranty.
Today is the day that I finally have time to do this! I've read through this entire thread multiple times, but with so many different responses on the "best" way to do this, I'm trying to finalize my method before I open the hood. My goal is to obviously do this correctly and avoid having to perform unnecessary relearns. All tips/advice would be greatly appreciated!
2012 G37 Sedan Journey 31k miles
1. Unplug negative terminal or leave it connected?
2. Open butterfly or leave it alone?
3. Should I do an ECU reset even if no codes are thrown?
4. If the ECU reset is recommended, is it better to do this immediately following the cleaning of the TBs/MAF or should I drive 5-10 miles and then perform the ECU reset?
5. Can someone help me out with a link for cleaning the MAF sensor?
2012 G37 Sedan Journey 31k miles
1. Unplug negative terminal or leave it connected?
2. Open butterfly or leave it alone?
3. Should I do an ECU reset even if no codes are thrown?
4. If the ECU reset is recommended, is it better to do this immediately following the cleaning of the TBs/MAF or should I drive 5-10 miles and then perform the ECU reset?
5. Can someone help me out with a link for cleaning the MAF sensor?
2. Yes open the butterfly and clean down in there good. Right where the butterfly closes generally has the most build up. Slowly guide the butterfly shut just to be safe.
3. As long as you don't unplug any thing no need to reset any codes. Not to mention you already pulled the neg terminal off
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Thanks for the write up, this was an easy task to preform with great reward. I no longer have a dropping idle and the response time in DS is much more impressive. Definitely quicker from a stop!
Thanks for the tips but I actually got impatient and knocked this out yesterday afternoon lol. As others have mentioned, the hardest part was getting the hex bolts off. I definitely recommend getting an extension for your allen wrench, it will make your life so much easier and your knuckles will thank you!
My TBs were absolutely filthy and I couldn't believe it! I figured there would be some buildup but nowhere near as much as what was actually in there. I disconnected the negative terminal before doing anything and took my time to ensure I didn't screw anything up. I also slowly opened the butterfly to to make sure I got everything and then guided it shut with my finger. After the TBs were cleaned I moved onto the MAF sensors which were extremely easy to remove/clean.
After reconnecting everything and verifying that all parts were properly attached, I took a deep breath and fired it up. RPMs went to about 2000 for a few seconds but slowly dropped down after about two mins. Before I took it for a test run I got cleaned up and then started it up again. CEL light came on after about 30 seconds so I turned the car off and performed the ECU reset. I failed my first attempt but nailed it on the second and then took my G for a joy ride. HOLY S***!!! It seriously felt like I was driving a completely different car. Everything was so much smoother and I couldn't believe how much quicker it became across the board.
I've driven 40 miles today and not only is the car so much more responsive/faster, my mpg has gone up significantly. Take the time and do this, you will be extremely happy with the results!!
My TBs were absolutely filthy and I couldn't believe it! I figured there would be some buildup but nowhere near as much as what was actually in there. I disconnected the negative terminal before doing anything and took my time to ensure I didn't screw anything up. I also slowly opened the butterfly to to make sure I got everything and then guided it shut with my finger. After the TBs were cleaned I moved onto the MAF sensors which were extremely easy to remove/clean.
After reconnecting everything and verifying that all parts were properly attached, I took a deep breath and fired it up. RPMs went to about 2000 for a few seconds but slowly dropped down after about two mins. Before I took it for a test run I got cleaned up and then started it up again. CEL light came on after about 30 seconds so I turned the car off and performed the ECU reset. I failed my first attempt but nailed it on the second and then took my G for a joy ride. HOLY S***!!! It seriously felt like I was driving a completely different car. Everything was so much smoother and I couldn't believe how much quicker it became across the board.
I've driven 40 miles today and not only is the car so much more responsive/faster, my mpg has gone up significantly. Take the time and do this, you will be extremely happy with the results!!
I was told by the mechanic that its better to just spray the cleaner into the TB and we should do it while the car is running, according to him too the reason why the TB is dirty its because of the cheap gas.
is that true?
is that true?
Did this today. Disconnected negative terminal then cleaned the Mafs and Tbs. I took the TB off the intake but never took off anything connected to it. I was pretty rough when cleaning it and at 32,000 miles they both had a bit of buildup on them. No issues after I put everything back together and started it up. Definitely noticed a better throttle response afterwards!
I've used this process and it works well...thanks for the write up. I'm almost at 70k and never cleaned the MAFs...what is the consensus on doing this? I've done it many times on my old Maxima, but have seen very little discussion on this forum. I've seen some threads saying it can harm the MAFs. Would appreciate any personal feedback or experience.
Just did my 08 with 51,981 miles on it and boy what a difference 
It started to pulsate at idle real hard.
And now its smoother and better power also wasn't that hard to clean.
Hear are some before and after pictures.
Passenger side before and after.

It started to pulsate at idle real hard.
And now its smoother and better power also wasn't that hard to clean.
Hear are some before and after pictures.
Passenger side before and after.
Just cleaned mine on Sat...Never cleaned before...Don't drive my car too much mostly weekends. It never had an idle problem....and not a lot of buidup after 7ys..but I did have this kinda bad hesitation if I went from low speed to full throttle...it would hiccup first then rev....now after I cleaned the TB...I can go to full throttle at any speed and no hesitation or hiccups now! AWESOME! she just pulls hard to redline. See how long it lasts. but if u have any of these kind of hesitations...clean your TB see if it helps. it did for me. and I never moved the TB blades...just sprayed a lot of cleaner in there. and wiped what I could. Since a lot of guy's had problems after moving the Blades.







