Been having this CEL come and go for a while now. Brought it to honda. They said it might be caused by my aftermarket header. Its a D16y7 so the o2 sensor is further away than it would normally be from the engine. Its a DC sports 4-2-1 header by the way, for a d16y8 engine. Does the d16y8 have a different primary o2 sensor? Or is my sensor just bad?

I had the number one spark plug wire come completely off the spark plug a while ago, causing some misfiring. Could that have screwed something up?

 

I think the O2 sensor is bad. Misfire can contribute to the demise of an O2 sensor.

 

Shouldn't the dealer be able to tell me if the sensor is bad? I feel like anytime i bring my car there they want to blame whatever is wrong with it on aftermarket parts. I knew there was a reason i hadn't brought it to the dealership in over 3 years.

 

If you needed to cut/splice the O2 sensor wires for the new header, bad wiring is another possibility. If so, make sure all the wires are soldered and insulated properly.