I have been reading up on here after searching. I just put a brand new engine harness in the other day complete stock and unmolested. I added a brand new honda factory o2 sensor and my car has been running awesome. Today coming home about 15 mins into my trip my car threw cel #1. The wiring is stock and the o2 is brand new and plugged in securely. My cat looks old as ***** and when this happended i could smell like a metal/ egg type of smell coming up from underneath. My question is could a clogged cat cause a brand new o2 to throw a code? The car is an EG hatch with a poor mans swap. Thanks

 

absolutely can...it can cause the o2 sensor to go bad and if the CAT is clogged it can cause a dramatic loss of power as well cause a head gasket to blow (worse case scenario)...just buy a new o2 sensor (assuming you ARE talking about the one that goes into the CAT) and get a stock replacement CAT...night and day difference

 

primary o2 is pre-cat...so i dont see how it could

 

well he didnt really specify..just said he put new o2 sensor

 

cel 1 is primary o2

 

my bad sir....not quite familiar with the CEL codes..i just know from experience that my rear o2 sensor went bad cause of my CAT

 

yes cel is primary o2, i am not a running a secondary and as to the best of my knowledge obd1 doesnt require a secondary o2. The question i have though is could a clogged or fryed cat cause a brand new factory o2 sensor to throw a cel like that, i have been told it has and im gonna replace the cat regardless i just wanted to if anyone has experienced this before or is that even a mechanical possibility. Thanks

 

anyone else any ideas???