ok long story short ive had a missfire thats unbearable:good fuel pressure,new opti,accel coil,good ICM,new ngk tr55,new taylor otvc.now when i went under the car i noticed my pass side o2 sensor harnes was severly burnt both of the harnesses had holes in them from heat and the metal prongs were black.they were bosch o2 now i have ac delco and what i did was cut the harnesses off the o2 sensor and the harness that clips into the o2 sensor and splice the wires together and used heat wrap around the wires to keep moisture out.now after 15 sec after start up i throw an ses code which i never threw before this.someone mentioned i could have messed up the resistance or sumthin but i had no choice.theres only 4 wires to splice with each other does anyone know which ones match to what??maybe i got 2 mixed up??

 

how did you connect the wires?

on the sensor was there a black, a grey and 2 white wires? you should be able to match it up lokking at the relationship of the old wires and where they are in the connetor.


You can scann and see what code you have and ake sure that it is from the 02's

 

Are you sure your misfire is an actual ignition misfire? Just something else to double check. Vacuum leak, bad fuel injector(s) ect. And splicing the O2 harness shouldn't be a problem. I had to extend mine cause of headers and have never had a problem. I would guess you could throw a code if you got the wires backwards though. Need to find out what the actual code is first though.

Ken R 95Z