1998-2008 Toyota Corolla Reported Problems:The Check Engine light with the trouble code P0171 is commonly caused by a failed or dirtymass airflow sensor. Symptoms include stalling and lack of power. Some owners reported that cleaning the sensor solved the problem, others said the sensor had to...
The Check Engine light with the trouble code P0138 is often caused by a bad rear oxygen sensor (B1-S2). The cost to replace it in a repair shop is around 1.0 hour of labor plus the part. An aftermarket sensor costs from $60 to $90, an OEM part is more expensive (up to $300)...