I am having problems with the front o2 sensor. The SES light was on and the codes were P0134 and P171 (no circuit activity and lean on accel.). I changed the o2 sensor with a brand new OE sensor from oxyensensor.com and it didnt help at all. I check the connector on the harness side with a volt meter and i am only getting a reading from one of the pins with the car on. Has anyone else had this problem? Just FRUSTRATED and trying to get this car running again.

 

Maybe you have a defective sensor?

 

Are you sure it is a bad O2 sensor, or are you just basing that off the CEL codes?

 

Before i bought the OE sensor i used a universal one and it was the same result.

 

You probably have a problem not related to the o2 sensor. Did you search around here for those codes to see the common symptoms/solutions?

 

Based off of the CELs, hooked up the car to a OBD2 scanner and it was reading 0.0 volts from the primary O2. Thought that is was the coil packs at first because when the car started to act up it would just die. Replaced them and then put a Walbro pump in it also hoping it was the problem.

 

Is your MAF plugged in all the way? do you have a cone? my MAF went bad, but I was running rich. dont know what, if any the code was though!

 

Yes i have searched and found that people that have the same CELs just repalced the O2 and fixed the problem.

 

You could have gotten a "bum" 02 sensor. I guess that is possible. good luck bro!

 

Glad to hear....

Sometimes car parts just love to give headaches,

 

I think he is saying the other people who have this issue replaced the part and the problem was fixed. In his situation he replaced it and it is not fixed.

 

I would try to find a wiring diagram and trace it back as far as you can. Then tone it out and see if maybe you have a broken wire or bad connection somewhere down the line.

 

Just found some info about a TSB:


2003 Mitsubishi LANCER 03 - Electrical System > ELECTRICAL SYSTEM [Part 110000 ]
TSB No: 03001 Replacement: NHTSA ID: , July 01, 2003
Summary: oxygen sensor harness corrosion - emissions recall. *tt

Does anyone know anything about this TSB?

 

I thought you said u fixed the problem?

 

I would call your dealership and see what they have to say about that TSB. There is a good chance they will be able to help.