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Check Engine Light

4 the ride

Active member
Joined
Dec 17, 2009
Messages
31
Location
Venice, Florida
Corvette
2015 Laguna Blue Z51
My 04 Z06 has a VaraRam cold air package. Recently I upgraded the air filter to their latest pleated and oiled replacement and in the process, I dry wiped some residue from the mass airflow body. I didn't touch the wire nor did I use any cleaners. Shortly after completing this upgrade I noticed some bucking when cruising in higher gears between 1,000 and 1,500 rpms. The car only has 15,000 miles and doesn't see much daily driving. Now the check engine light is illuminated. I stopped by a Advance Auto Parts store and they were kind enough to plug in an OBD2 reader and found that "bank 1" was indicating a lean condition. He explained that this was a reading from one of the O2 sensors. I have a set of Melrose Headers, Random Technologies high flow cats, an X-pipe and a Corsa cat back system. The work was done a number of years ago before I purchased the vehicle from it's original owner. When reviewing the receipts for this work, I noted that they installed a couple of O2 "simulators," when completing this work. Ok, having said the aforementioned can anyone help me with a potential cause for the illuminated check engine light? BTW, we cleared the code but it promptly returned within ten miles of driving. The car seems to run fine but.....what to do?
 
My 04 Z06 has a VaraRam cold air package. Recently I upgraded the air filter to their latest pleated and oiled replacement and in the process, I dry wiped some residue from the mass airflow body. I didn't touch the wire nor did I use any cleaners. Shortly after completing this upgrade I noticed some bucking when cruising in higher gears between 1,000 and 1,500 rpms. The car only has 15,000 miles and doesn't see much daily driving. Now the check engine light is illuminated. I stopped by a Advance Auto Parts store and they were kind enough to plug in an OBD2 reader and found that "bank 1" was indicating a lean condition. He explained that this was a reading from one of the O2 sensors. I have a set of Melrose Headers, Random Technologies high flow cats, an X-pipe and a Corsa cat back system. The work was done a number of years ago before I purchased the vehicle from it's original owner. When reviewing the receipts for this work, I noted that they installed a couple of O2 "simulators," when completing this work. Ok, having said the aforementioned can anyone help me with a potential cause for the illuminated check engine light? BTW, we cleared the code but it promptly returned within ten miles of driving. The car seems to run fine but.....what to do?

Can you clarify some of your information? You state that there is some "bucking" between 1k and 1.5k, but then say in the end "the car seems to run fine but...".

CG
 
Z06 Check Engine Light

Can you clarify some of your information? You state that there is some "bucking" between 1k and 1.5k, but then say in the end "the car seems to run fine but...".

CG

CG, Thanks for your reply. I hadn't noticed this prior to the VariRam work but it feels like the timing is advanced, it's slight and most noticeable in sixth gear. Don't know if this is related to the OBD2 code or not.
 
My initial guess would be that due to the minor modifications done to your vehicle to help it "breath" better, it is now running lean. The 10% Ethanol (or more) in our fuel now does not help the situation. If your computer tune / calibration was not change or modified to take advantage of the cat-back exhaust and the other modifications, then the computer was probably on the verge of "throwing" a lean code. Now, for some reason it has decided to log a lean code.

There could be other factors affecting your particular situation, but it is difficult to say with the current limited information.

I did some minor bolt-on mods and retuned my computer and set the AFR to 14.1, which is about where the air / fuel ratio needs to be for our 10% Ethanol fuel to avoid detonation / pinging.

CG
 
My initial guess would be that due to the minor modifications done to your vehicle to help it "breath" better, it is now running lean. The 10% Ethanol (or more) in our fuel now does not help the situation. If your computer tune / calibration was not change or modified to take advantage of the cat-back exhaust and the other modifications, then the computer was probably on the verge of "throwing" a lean code. Now, for some reason it has decided to log a lean code.

There could be other factors affecting your particular situation, but it is difficult to say with the current limited information.

I did some minor bolt-on mods and retuned my computer and set the AFR to 14.1, which is about where the air / fuel ratio needs to be for our 10% Ethanol fuel to avoid detonation / pinging.

CG

CG, thanks again for your insight. Sounds like you are on to something, how much leeway would a shop mechanic have in richening the mixture. I have an appointment to have it looked at Monday morning. Can this be adjusted via an OBD2 reader device? Interestingly, the mods were originally applied way back in 05 and haven't been touched since, other than my recent air filter work. Also, why would only one bank (bank 1 - is this left or right?) seems to be affected.

FTR
 
To adjust / modify the PCM software you'll need third party software / hardware from companies like HP Tuners or EFI Live, etc. I am not associated with any of these companies.

You could also seek out someone who does PCM tuning, which is quit common. You should be able to find someone easily in Florida. They would charge you a nominal fee, but it may be worth it if you do not have the desire or inclination to get into "DIY tuning".

Bank 1 is the drivers side. Both banks probably have a lean condition, but the PCM has deemed it bank 1 due to the period / time of the knock in relation to sensor input, in this case the crankshaft sensor and possibly other sensor information. If you drove the car long enough and hard enough in the upcoming hot weather, you would probably get lean codes on both banks.

CG
 

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