I have been getting a code 1 for awhile now still to no end. I have bought a new o2 sensor and still pops code. I have an exhaust on the car with no cat just a resonator and test pipe back to muffler. My mechanic told me that if the o2 sensor can't heat up enough without the back pressure it could be a cause. I never had this problem before and now it became a problem. Any ideas as to what I can check. Any advice is greatly appreciated.

 

Im assuming you are running a single-wire o2? please provide a little more information.

I would trace all the wiring back and make sure you have secure connections..

 

ya I have a single wire connection. The o2 sensor doesn't kick till I drive after about 5 mins. or so.