6spdLEGEND

On my dad's 3.0CL, we had the secondary oxygen sensor a month ago or so when I got error 63. He was driving on that error 63 for about 3 months before replacing the O2 sensor. Since the 3 months prior to changing the O2 sensor I did not check the codes again.

After replacing the secondary O2 sensor, the Check Engine light remains on, so I pull the code again and find an error 41 which was left for a month before replacing hte primary O2 sensor.

For the entire day there were no more check engine light coming on. At the end of the day the damn check engien light came on again! Showing me an error 63 again! Does this mean the secondary O2 sensor I put in a month ago has already gone bad? What else can it be?

Please guys, I need help as I'm stumped on whether I should replace the O2 sensor again (under warranty though), perhaps test it with a multimeter for the proper resistance tolerances, or is it my cat?

Thanks in advance!

niedejb

Running excessively rich can foul these. May be other problems.

6spdLEGEND

If I was running rich, wouldn't I also get an error code 43 - Air/Fuel too Rich/Lean?

Perhaps my mass air flow sensor is shot causing the ECu to send alot of extra fuel?

Any chance my Cat is shot?

I will do the first thing and have the secondary O2 sensor replaced again (since it's under warranty) and I'll go from there.

Thanks.