P0157 Chevrolet -

Question

hello i changed both cat conv and all four sencers .engine light still came on then i replaced the sencer again in the rear on the driver side check engine light went out for about two weeks and now the engine light is on again the code is po157 i drive a chevey avalanche 2002 1500 5.3 engine can you help strong text

Answer 1

have you check for intake leaks? look for broken, cracked or loose hoses. You can try to clean the mass air flow sensor with mass air flow sensor cleaner, check fuel pressure (see specs below). Try using 91 octane fuel from shell and use a good fuel system cleaner.

Possible causes:
- Faulty Rear Heated Oxygen Sensor Bank 2
- Rear Heated Oxygen Sensor Bank 2 harness is open or shorted
- Rear Heated Oxygen Sensor Bank 2 circuit poor electrical connection
- Inappropriate fuel pressure
- Faulty fuel injectors
- Intake air leaks may be faulty
- Exhaust gas leaks