I own a 2003 F-150 4.2 engine 2 wheel drive extended cab. I need some help on finding an easier way to get at the O2 sensor connector on bank #2. I am having a trouble code of P0171 and want to check the sensor to see if it is working.
The reason I want to check the O2 sensor is because the fault code indicates a lean condition in bank #2. I have checked for vacume leaks and did not find any. I also cleaned my MAF sensor and the check engine light is still on.
I am suspecting that it could be a lazy O2 sensor. The problem is getting to the O2 sensor connector which is tucked behind the engine next to the fire wall.
You don't understand!
The OX sensor is only reporting the trouble.
It's not the troube it'self.The sensor is the only way the system has to report the problem to you via a code and light.
Look at the code discription.
It says 'LEAN'.
This is not the sensor's fault. It's only detecting the problem.
There is a fault on the intake side your failing to find. Could be an air leak or lack of or even to much fuel causing the OX sensor to detect an oxygen content out of limits.
The sensor trys to correct by shifting the fuel table too far 'lean', setting the code. This is where the 'lean' comes from.
Lean in this case means the computer software fuel table is shifted to it's lean end out of limits. This is what sets the code, not the OX sensor.
If you choose to see it differently, have a good time until you accept it..
The v6 has some areas prone to air leaks.
No it has no miss and someone said it might have a leak in the intake or plenum.
When I cleaned the MAF sensor the light went away. I also looked at the O2 wave form and saw that the up stream sensor was not responding at 2500 RPMs. I sprayed starter fluid and heard no difference in RPM change.
OK, I understand there may be some other problem with the lean condition and that a rich condition may be the problem. So where would be a good place to start looking? The lean condition is in the #2 bank which I believe it to be the driver side.