ODBII Diagnostic Codes

1) P0141 O2 Sensor Heater Circuit Bank 1 Sensor 2
2) P0401 Exhaust Gas Recirculation Flow Insufficient Detected
3) P0441 Evaporative Emission System Incorrect Purge Flow

For the second and third codes what would cause that? Do the problems stem from the O2 sensor? Unfortunatly I failed an inspection because of these and I did not even know there was a problem because the check engine light bulb burn out. :banghead:

O2 has nothing to do with the other codes. 401 relates to the egr not opening sufficiently when commanded to get the proper map or maf return readings, or the passages are blocked, 441 is what it says, purge valve or circuitry is faulty.

How can I tell if the egr valve is just bad or if its just dirty?

What year s the car?

1996

The egr can be tested with a bidirectional scanner or by grounding the circuits at the egr which will make it open and the engine stumble if it is working. A wiring diagram is needed for the latter