Okay everyone. Replaced both upstream sensors (Delphi sensors), cleaned Mass Airfow Sensor, changed fuel pump and filter (Delphi pump). Runs a little better however I am still getting a P0171 System Too Lean Bank 1.

What else could be the cause here? I can clear the CEL upon start up with a scan tool but when I shut it off and start it back up the CEL comes back.

 

can you monitor fuel trim with your scan tool?

 

I don't think I can do that with my scan tool. But that code went away and it gave me 6 codes.

P0030 HO2s Heater Control Circuit (Bank 1 Sensor 1)

P0050 HO2s Heater Control Circuit (Bank 2 Sensor 1)

P0134 O2 Circuit No Activity Detected (Bank 1 Sensor1)

P0135 O2 Heater Circuit (Bank 1 Sensor 1)

P0154 O2 Circuit No Activity Detected (Bank 2 Sensor 1)

P0155 O2 Heater Circuit (Bank 2 Sensor 1)

 

how many wires do the o2 sensors have, 4? check the 02 heater fuses.

 

Yes 4 wires. Where are these fuses locates you know? I might have to research this.

 

Okay replaced the fuse and all O2 codes gone except P0171 System Too Lean Bank 1 and P0174 System Too Lean Bank 2.

I just dumped seafoam into the tank gonna let it clean the fuel system and injectors see what happens. Any other ideas on these two codes?