Air Fuel Sensor Replacement

[Andrews Chalmers]

We recently had a service engine soon light, which was attributed to a P2A00 error code. The dealer replaced the air-fuel sensor (22693-1AA0B) & reprogrammed the ECM (DE98AA & DE53AA).

Was wondering if anyone could provide some info on exactly what the ECM reprogramming entails (perhaps some sort of TSB? or perhaps what section of the Service Manual I should refer to).

I guess the bad air-fuel sensor may help explain why there was a dip in the engine smoothness & mpg...

[biggie]

Guess you mean an O2 sensor. And yes that can cause the car to run poorly and dump extra fuel, resulting in bad mpg.

Assume that they would only need to reset the ECU, unless something has been discovered that the fuel management is off in the ECU and they are trying to correct it, but haven't heard of any of that.