Aftermarket Exhaust Installed & Service Engine Light Came on
 

On Saturday I installed a slightly used OEM Nismo CBE on my Z. I bought it from one of the other members on here. It only has around 2000 miles on it and looks brand new. Installation was a cinch. Took only about 35 minutes. After the install I drove the car for over an hour from Virginia to Baltimore with no problems. On Sunday I went for a 5 minute drive and the Service Engine Soon light came on. It came on and stayed on. When I got back to my house I remembered I forgot to reset the computer after the CBE install, so I disconnected the negative battery terminal and depressed the brake pedal to drain whatever was left in the system. After about a minute I reattached the cable. When I started the car the light was off. I figured, Problem solved! Wrong.

Today I went for a drive and within in 5 minutes the light came back on. I honestly can’t see how a stock Nismo CBE would cause this issue. I only disconnected the battery for about a minute. Should I do this for a longer period of time? I’m afraid if I bring it to the dealership they are going to give me a hard time about the mod. My Z only has 2075 miles on it and I haven’t done any other mods. I also read the owner’s manual and it said to check the gas cap. I did and it was on tight.

Any suggestions or thoughts on this?

chances are it's not the exhaust causing the problem.... just happened to throw a code after the install of the new exhaust. Read the code and then you will know. Or change out the exhaust to stock and see if it goes away... but it is possible you have another problem

Well that would be a big coincidence. Any where I can take the car to find out the code, other then the dealership?

I would check and re-torque all exhaust connections, I would assume any decent local mechanic can check the code for you.

Autozone will check codes for free, but they won't clear codes.

Out of curiosity, how would an exhaust leak in a CBE throw a code? The CBE is after the O2 sensors, so how would it detect this? A loss in back pressure?

Agreed, there arent any sensors at all behind the cats, im willing to bet youre probably running a rich/lean condition and its probably triggering the code, throw some G3 intakes on it and maybe it'll balance out! Go to autozone and have them check the code and report back.

Are you taliking about the "Check Engine" light which indicates a fault, or the Service reminders in the left side pod?

If the latter it's just a coincidence. Re-set them to the proper mileage intervals per the Owners manual. If it is the CEL, then get the code read and correct the problem.

It's the "Service Engine Soon" light (CEL) in the center. It's not in reference to the service reminders. I'll go to AutoZone tomorrow and get the code.

I really think this Z is cursed. So little mileage and so many problems.

try leaving your battery neg cable off for more than a minute, try half an hour or longer if your not in a rush, then if it throws a code again you can get it read.....also if you used an impact gun or were rough with the bolts when taking off the stock exhaust you may have damaged the catalytic converter sensor = $$$

We were pretty careful to not touch the sensors. I'll disconnect the batter for at least 30 minutes tomorrow and then I'll take it for a ride. If it comes on, I'll head over to AutoZone to get the code. I'll post the results.

Thanks everyone!

I wouldn't bother with disconnecting the battery again. If the cel is on it is best to read the code and find out the exact cause.

:iagree: If the disconnect was long enough to reset the light then it reset everything. Just get the code read, takes 5 minutes.

Finally made it over to AutoZone. They said the light is on because there is an issue with the second O2 sensor in bank one. If I'm correct, that's the one on the driver's behind the cat. I guess I could have bumped it while doing the CBE install. I'll put it up on the floor jack tomorrow and check the connection. I've never messed with 02 sensors before, is there anything I should know or to look for?

Given that you have stock cats, it's either something you did to the sensor or you have a leak where the exhaust mates with the cats. Did you use new exhaust gaskets?