M2 Header and Now P2A00 and P2A03 DTCs.

[b16sentra]

Hey everyone,

Maybe there are some others out there with a similar problem. I installed my M2 Racing header and midpipe combo about 10 days ago, along with appropriate secondary O2 simulators and everything went together fine. I used a new OEM manifold gasket and the m2 supplied gaskets for the midpipe. I also have an Injen cold air intake installed from about 2 months ago that hasnt given me any problems.

Since the install, however, I have been throwing P2A00 and a P2A03 codes, signalling an issue with the main A/F sensors failing a self-diagnostic test. I do not have any other codes besides these and they come up consistently and at the same time (together). I have tried relocating the O2 sensors in both sets of bungs in the header (no change), I have tried a new manifold gasket(no change), and I have had the car to my local tuners to have them troubleshoot(no answers).

The only info I have been able to get from anyone is that my O2's are reading lean when the ECM does its diagnostics and this is tripping the codes. The problem is no one can give me an answer as to why! Has anyone else installed this combo of parts without issue? I am starting to think that the ECM just flat out doesnt agree with the free-flowing intake and exhaust and is seeing this combo as a problem.

What I hope is that there are some others out there who have fought this issue and figured out a solution or can point me in some directions to take my troubleshooting.

Thanks!