P1124 P1126 Codes

[rule1]

Could these codes P1124 and P1126 be caused by one bolt on a header being broke?

[paulv]

P1124 is a fuel pump relay code and if it's faulty, it could cause the engine to starve for gas causing a lean condition (thus the P1126 bank 1, but I would expect P1133, bank 2 to be set also).

It is possible that the P1126 is set because the exhaust system has a leak upstream from the front O2 sensor causing that sensor to detect more O2 and then having the DME compensate for a "perceived" lean condition.

How does the car run? Does it feel like it's starving for fuel?

Regards,
paul...

[rule1]

The car runs great.. I just put a cold air intake,Headers and muffler on it (2.5 99') for my buddy. AOS is good and no smoke.

[thstone]

These codes mean that the ECU has continued to enrich (add fuel) the air/fuel mix to the maximum extent possible to compensate for a lean condition (more air than fuel is sensed by the O2 sensors as compared to what the MAF is sensing).

So my bet is that you have an air or vacuum leak somewhere.

I think that Paul is right - a possible leak in the exhaust manifold could be sensed by the downstream O2 sensor as additional air coming from the combustion chamber and be interpreted by the ECU as a lean running condition.

I'd suggest repairing the potential exhaust manifold leak but also checking for air or vacuum leaks on the intake side.

[rule1]

My buddy said yesterday he was in first gear and it kinda started revving up on its own..Any ideas what that could be? Also said no CEL in 2 days.. Then today the same P1124 and P1126 when it was idling. Still running great though.