Hi! New to the site. I need some suggestions. I have a 01' f150 4.2v6. Had the famous lean bank 1 and 2 and 02 sensor codes (both downstream). Looked for vacuum leaks and did not find any. Decided to replace the plenum gaskets and bolts. While the plenum was off I noticed a broken clip on one of the intake flap linkage so I replaced all 4 clips and cleaned the crud in the intake. Lean bank 1 and 2 code is gone and runs alot better however I still have both 02 sensor downstream codes coming up and they have been replaced. I noticed on my scanner that they dont seem to be responding. All wires seem fine. They are Bosch 02 sensors. Dont know if that may be the problem. Any advice would be appreciated. Thanks!

 

I'd take it into Ford, spend the $80 and let them pinpoint it. I had the infamous P0174 code forever. No leaks, etc. Took it to them and they diagnosed it to a bad catalytic converter. I changed it and got my mileage back.

 

Please post the exact numeric codes..........

 

Sorry! I am not used to this forum. I didnt get an email telling me someone answered my question. Anyway the codes are:
- P0141 02 Circuit Bank 1 Sensor 2
- P0132 02 Circuit Bank 1 Sensor 2
- P0156 02 Circuit Bank 2 Sensor 2
Both downstream 02 sensors are brand new. I even replaced the Bank 1 twice thinking that it was defective.
Thanks for the response.
-Matt

 

Your interpretations are a bit off.

P0141 - Oxygen Sensor Heater Circuit Malfunction (Bank1, Sensor2)

http://www.obd-codes.com/p0141

P0132 - Oxygen Sensor Circuit High Voltage ( Bank1, Sensor1)

http://www.obd-codes.com/p0132

P0156 -Oxygen Sensor Circuit Malfunction (Bank 2 Sensor 2)

http://www.obd-codes.com/p0156

Those codes are for 3 different sensors. Read the links for causes. Bank 1 is passenger side and sensor 1 is the upstream sensor (closest to the engine).

 

Oops! I guess I wrote it down wrong. What should I do? Replace the bank 1 sensor 1? Like I said both downstream 02 sensors have been replaced and I dont see any wiring issues.

 

Down stream sensors won't effect fuel trims, they are ther just to monito catalyst efficiency

 

Did you read each link?