G37x Service Engine Soon
03-20-2018, 01:52 PM
#16
2.1 If they were going bad, you would have had other indicators before now. Bad smell coming from the cats is a big one. Plus you might have gotten some O2 sensor CELs, which you do appear to have.
3. Ruin your 'Air fuel ratio sensors' otherwise known as O2 sensors? Again, doubtful, however, it is possible depending on how long you have been driving it like this.
4. Back to stock intakes? You're probably fine with what you have, however it is my personal belief that no kid behind the desk at Autozone selling CAIs is smarter than the team of engineers with years of experience, and loads of degrees. Believe me when I tell you, the engineers did everything they could to get as much performance as they could, which is why the g37 has dual intakes and the 35 has only 1.
5. New cats? I would not be in a huge hurry to do that. That right there is easy for him to say, and fix, but hard for you to pay for. you need to to do more research on bad cats.
6. New O2 sensors? Again, don't be in a rush to throw a ton of parts at the problem.
7. $2k for new cats, sensors, and a reflash? That actually doesn't sound bad, he may not know what the actual problem is, but at least hes inexpensive!
8. Salty? yeah, I get that. But when you mess with the computer, you're rolling the dice.
9. Lose your license? I cannot answer this one. but my educated guess is that you do not lose your licensee... for that one particular tune, which frankly, it sounds like is a bad tune anyway. you will however have to pay again to have it re-implemented/uploaded, which will be significantly cheaper than the initial cost. That is just a guess though.
10. Aftermarket cats? There are two components here. 1, aftermarket cats will be like any other aftermarket part. there are some good, some bad. Find some with a warranty. The second part here is that mechanics markup parts on the bill. that is just a fact. It's part of how they generate revenue. So if you don't buy their parts, they miss out on money...maybe now you are seeing why they want to use their parts. BUT if you buy parts, not only may they not even put them in, (they usually will though) but they will definitely not warranty the parts later.
11. Aftermarket cats cause CELs? Maybe, but I have never heard of that before. But you know what scares most people? CELs Scaring people into doing work they don't need is an age old practice of mechanics everywhere.
12. One brand of cats better than any other? eh. Shop around. Good parts come with good warranties. check with Rock Auto and amazon, both have something of a rating system for their parts.
What I actually suggest:
Plan A: Follow my previous advice about the scanner. Find the Cylinder with the problem. Find out if it's a fuel injector, or if its a plug/coil. IF it is not any of those three, reflash back to stock, and test drive for a bit.
Plan B: Pay a mechanic to give actually live data on his scanner to find which cylinder is misfiring. If it's consistently one cylinder, attack that cylinder. (look at if it's a fuel injector, or if its a plug/coil). This will cost you about as much as a scanner would but he will know exactly how to use it, and how to narrow it down to the right cylinder. IF it does not narrow down to any one particular cylinder, reflash to stock, and test drive.
Plan C: Reflash and drive to see if you get more codes. You don't HAVE to get the cats, O2s and reflash all done at the same time.
3. Ruin your 'Air fuel ratio sensors' otherwise known as O2 sensors? Again, doubtful, however, it is possible depending on how long you have been driving it like this.
4. Back to stock intakes? You're probably fine with what you have, however it is my personal belief that no kid behind the desk at Autozone selling CAIs is smarter than the team of engineers with years of experience, and loads of degrees. Believe me when I tell you, the engineers did everything they could to get as much performance as they could, which is why the g37 has dual intakes and the 35 has only 1.
5. New cats? I would not be in a huge hurry to do that. That right there is easy for him to say, and fix, but hard for you to pay for. you need to to do more research on bad cats.
6. New O2 sensors? Again, don't be in a rush to throw a ton of parts at the problem.
7. $2k for new cats, sensors, and a reflash? That actually doesn't sound bad, he may not know what the actual problem is, but at least hes inexpensive!
8. Salty? yeah, I get that. But when you mess with the computer, you're rolling the dice.
9. Lose your license? I cannot answer this one. but my educated guess is that you do not lose your licensee... for that one particular tune, which frankly, it sounds like is a bad tune anyway. you will however have to pay again to have it re-implemented/uploaded, which will be significantly cheaper than the initial cost. That is just a guess though.
10. Aftermarket cats? There are two components here. 1, aftermarket cats will be like any other aftermarket part. there are some good, some bad. Find some with a warranty. The second part here is that mechanics markup parts on the bill. that is just a fact. It's part of how they generate revenue. So if you don't buy their parts, they miss out on money...maybe now you are seeing why they want to use their parts. BUT if you buy parts, not only may they not even put them in, (they usually will though) but they will definitely not warranty the parts later.
11. Aftermarket cats cause CELs? Maybe, but I have never heard of that before. But you know what scares most people? CELs Scaring people into doing work they don't need is an age old practice of mechanics everywhere.
12. One brand of cats better than any other? eh. Shop around. Good parts come with good warranties. check with Rock Auto and amazon, both have something of a rating system for their parts.
What I actually suggest:
Plan A: Follow my previous advice about the scanner. Find the Cylinder with the problem. Find out if it's a fuel injector, or if its a plug/coil. IF it is not any of those three, reflash back to stock, and test drive for a bit.
Plan B: Pay a mechanic to give actually live data on his scanner to find which cylinder is misfiring. If it's consistently one cylinder, attack that cylinder. (look at if it's a fuel injector, or if its a plug/coil). This will cost you about as much as a scanner would but he will know exactly how to use it, and how to narrow it down to the right cylinder. IF it does not narrow down to any one particular cylinder, reflash to stock, and test drive.
Plan C: Reflash and drive to see if you get more codes. You don't HAVE to get the cats, O2s and reflash all done at the same time.
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G37xBrock (03-25-2018)
03-25-2018, 04:58 PM
#17
Registered Member
Thread Starter
Hey look, another update:
So I finally took it to an Infiniti dealership yesterday in order to have them run diagnostics in hopes of getting my cats replaced under the federal emissions warranty. They said one of the cats qualified so I'm waiting for that part to get installed which should hopefully be in the next 2-3 days. Turns out, it may not have been a tune causing the car to run rich/lean. Infiniti found that at one point or another, someone used an incorrect bolt on the intake manifold which over time caused it to crack. I'll have to pay roughly 500-600 for this to get replaced but that beats paying over a grand for the cat work. I intend to follow up with them after the work is done to see what I need to do about the air fuel ratio sensors that are bad. With one new cat I can at least have one done (hoping maybe this gets replaced with the cat under the warranty? The service adviser hadn't ordered the parts yet and wasn't certain if this would be included or not).I'm hoping when they test drive the car after they finish the install, the light will come back on and they'll go ahead and replace the other one so I can close the book on this ongoing headache. If not, I've still got 2 years and about 20,000 miles left to qualify getting them replaced free.
My local mechanic was going to reflash my ECM back to stock but it was locked out. He suggested I either get a new unit or take the car to get tuned by a shop that has a good history of working with Nissan/Infiniti cars. I will probably do the latter since I already spent the money on the uprev license and since I already swapped my Stillen CAI out for the stock intakes.
Should have more information when the car is ready between Tuesday and Thursday of this week. Trying to document as thoroughly as possible in the event someone else has a similar experience at some point. Special shoutout to Michael_in_DE for the tips and explanations as well! Appreciate it, man.
So I finally took it to an Infiniti dealership yesterday in order to have them run diagnostics in hopes of getting my cats replaced under the federal emissions warranty. They said one of the cats qualified so I'm waiting for that part to get installed which should hopefully be in the next 2-3 days. Turns out, it may not have been a tune causing the car to run rich/lean. Infiniti found that at one point or another, someone used an incorrect bolt on the intake manifold which over time caused it to crack. I'll have to pay roughly 500-600 for this to get replaced but that beats paying over a grand for the cat work. I intend to follow up with them after the work is done to see what I need to do about the air fuel ratio sensors that are bad. With one new cat I can at least have one done (hoping maybe this gets replaced with the cat under the warranty? The service adviser hadn't ordered the parts yet and wasn't certain if this would be included or not).I'm hoping when they test drive the car after they finish the install, the light will come back on and they'll go ahead and replace the other one so I can close the book on this ongoing headache. If not, I've still got 2 years and about 20,000 miles left to qualify getting them replaced free.
My local mechanic was going to reflash my ECM back to stock but it was locked out. He suggested I either get a new unit or take the car to get tuned by a shop that has a good history of working with Nissan/Infiniti cars. I will probably do the latter since I already spent the money on the uprev license and since I already swapped my Stillen CAI out for the stock intakes.
Should have more information when the car is ready between Tuesday and Thursday of this week. Trying to document as thoroughly as possible in the event someone else has a similar experience at some point. Special shoutout to Michael_in_DE for the tips and explanations as well! Appreciate it, man.
03-26-2018, 08:48 AM
#18
One of the Cats qualified? That means unburnt fuel was probably getting dumped by that bank, and that is what ruined the Cat. Unburnt fuel is a result of a misfire, (which is a code you are getting) in which either the plug or coil is not firing and the fuel is still being processed through, this could also be a result of the injector staying open inf the plugs and coils are working as they should.
Bad bolt? Cracked intake? Whoa. Where did that come from? I could be wrong though. Did they show you this? That sounds like some bs right there.
Bad o2 sensors? They may not be bad. They did their job. They detected an abnormality in the exhaust (excess unburnt fuel). Once the misfire is corrected they may go back to working as they should.
Out of everything it sounds like they are still not addressing the misfire, which is the cause of everything. Unless they think the abnormal bolt/manifold is the issue, which I would be SHOCKED if it was. My money says, within 30 days of getting your car back, you will get another P0300 CEL with a misfire. And if that is the case it will continue to ruin your NEW cat.
But hey, thanks for the shout out, I appreciate it. Hopefully I am wrong and the new manifold and bolt fixes you completely.
Bad bolt? Cracked intake? Whoa. Where did that come from? I could be wrong though. Did they show you this? That sounds like some bs right there.
Bad o2 sensors? They may not be bad. They did their job. They detected an abnormality in the exhaust (excess unburnt fuel). Once the misfire is corrected they may go back to working as they should.
Out of everything it sounds like they are still not addressing the misfire, which is the cause of everything. Unless they think the abnormal bolt/manifold is the issue, which I would be SHOCKED if it was. My money says, within 30 days of getting your car back, you will get another P0300 CEL with a misfire. And if that is the case it will continue to ruin your NEW cat.
But hey, thanks for the shout out, I appreciate it. Hopefully I am wrong and the new manifold and bolt fixes you completely.
03-28-2018, 04:07 PM
#19
Registered Member
Thread Starter
One of the Cats qualified? That means unburnt fuel was probably getting dumped by that bank, and that is what ruined the Cat. Unburnt fuel is a result of a misfire, (which is a code you are getting) in which either the plug or coil is not firing and the fuel is still being processed through, this could also be a result of the injector staying open inf the plugs and coils are working as they should.
Bad bolt? Cracked intake? Whoa. Where did that come from? I could be wrong though. Did they show you this? That sounds like some bs right there.
Bad o2 sensors? They may not be bad. They did their job. They detected an abnormality in the exhaust (excess unburnt fuel). Once the misfire is corrected they may go back to working as they should.
Out of everything it sounds like they are still not addressing the misfire, which is the cause of everything. Unless they think the abnormal bolt/manifold is the issue, which I would be SHOCKED if it was. My money says, within 30 days of getting your car back, you will get another P0300 CEL with a misfire. And if that is the case it will continue to ruin your NEW cat.
But hey, thanks for the shout out, I appreciate it. Hopefully I am wrong and the new manifold and bolt fixes you completely.
Bad bolt? Cracked intake? Whoa. Where did that come from? I could be wrong though. Did they show you this? That sounds like some bs right there.
Bad o2 sensors? They may not be bad. They did their job. They detected an abnormality in the exhaust (excess unburnt fuel). Once the misfire is corrected they may go back to working as they should.
Out of everything it sounds like they are still not addressing the misfire, which is the cause of everything. Unless they think the abnormal bolt/manifold is the issue, which I would be SHOCKED if it was. My money says, within 30 days of getting your car back, you will get another P0300 CEL with a misfire. And if that is the case it will continue to ruin your NEW cat.
But hey, thanks for the shout out, I appreciate it. Hopefully I am wrong and the new manifold and bolt fixes you completely.
When I went to pick up my courtesy car after they diagnosed my car last week, I had them show my the crack in the manifold as I was curious and didn't want to be getting hustled or anything like that. Sure enough, it was indeed cracked.
Talked to the service adviser today who told me I shouldn't need to worry about replacing any sensors right now. They test drove the car for about 20 miles and said nothing felt wrong and no lights came on. I know you said you'd be shocked if the manifold was the sole issue for the code but I previously read on a 370z forum how many different things the p0300 can be caused by and there was a surprisingly similar saga to mine over there. Wish I could find the link but I have yet to run across it again.
Anyway, I'll continue driving the car as normal based on both Infiniti and my mechanic saying it should be fine and hopefully I can finally close the book on this drawn out headache. As before, I'll report back on any other issues that arise in order to keep a well documented history in the event someone else runs into a similar situation in the future.
03-28-2018, 04:57 PM
#20
I suppose excess unmetered air COULD (and apparently did) cause a misfire. That must have been quite the crack! I am glad they did not push the sensors on you, and that they seem to be ok. Not a regular tactic of a dealership to NOT push parts. Sounds like it might be an ok place to go in the future.
Well, I am glad it seems to be fixed. Now, to track down the dumbass that over-tightened the wrong bolt on the manifold!
Well, I am glad it seems to be fixed. Now, to track down the dumbass that over-tightened the wrong bolt on the manifold!
09-19-2019, 06:16 PM
#21
Registered Member
My 2011 sedan is throwing this code (P0725). My car hasn't stalled. Nothing seems serious. It's shifting just seems to lag sometimes. And when accelerating from a stop i have to push the gas pedal down further than usual to get it to go.
Just feels like it should be running better.
Anyone think I should get the ECM update before i think about replacing the camshaft sensor?
Just feels like it should be running better.
Anyone think I should get the ECM update before i think about replacing the camshaft sensor?
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