Reading Lean/ Bank 1, Is it O2?

[stngmn96]

Hey there Stangers!

I have had this happen before and replaced my 02 sensors and it goes away. This time however, I have changed 3 of 4 sensors, including all of them on the passenger side which I was told was Bank 1. I have changed the fuel filter and still the light is on. My only thought is that I still need to replace the one sensor remaining on the drivers side before the cat's. I am going to change out the PCV next. Can anyone tell me if it is reading lean on the Air or Fuel mix. I am not sure what "lean" is meaning. Fuel Regulator settings haven't changed in years and so I am sure that isn't the case. Where should I look next? Any suggestions? I would appreciate some ideas and help, as I am doing this stuff on my own. Thanks everyone!

 

[Mike97gt]

many things can cause a lean code. first thing you need to do is get live data readings from the PCM and check these too pids..

LTfueltrim bank1 and LTfueltrim bank 2

if they are both lean but bank 2 has not set a code then you most likely have a vacumm leak or a maf problem..

if only bank 1 is lean then you could have exhaust leak on that bank.. or a misfire on that bank will cause one bank to read lean since the 02 sensor only picks up the unburn oxygen of a misfire.

BTW 999 out of 1000 times lean codes are not o2 sensor problems.. in fact I have never seen a lean or rich code fixed with 02 sensors. the way the PCM stragy works if the sensor is bad you will most likey get a sensor indicates lean or rich code.. this is a different code than the po171 lean bank one code..

One last thing.. replacing the one reamining sensor on the drivers side ( bank 2) will nto fix this problem.

 

[OV10stang]

Check for an exh leak also, fwd of the O2 sensor, had it happen to me.

 

[Mike97gt]

Check for an exh leak also, fwd of the O2 sensor, had it happen to me.

yeah I said that too. if it's only lean on bank one then thats the most likely cause. ( you must verify this with a scan tool.. it may only have bank 1 code but bank 2 might be at + 23 fuel trim and about to set a po174 lean bank 2 any minute)