ok, so here's the deal. the car is a 96 civic ex converted to obd1(running a chipped P28), cat removed, secondary o2 sensor removed. the check engine light comes on a few seconds after start-up... so i change the primary o2 sensor(the one that goes on the header), reset the ecu, and i still get a check engine light.... i check the code again and it still gives me code 41... is there anything i'm doing wrong???

 

How did you go about resetting the PCM?

 

disconnecting the negative terminal on the battery for about 10 mins.

 

Did the check engine light come immediately back on?

 

just like it did before. after the motor runs for a couple seconds.

 

Remove your PCM fuse for a few minutes. If that does not get rid of the light it means you have not yet fixed your problem.

 

i'll do that now. thanks.

 

pulling the backup fuse, pulling the ECU and removing the negative terminal of the battery are all going to result in the same thing.
resetting the ECU.
Pulling the fuse or negative terminal for anything more than 30 seconds is only a waste of time. UNLESS you have an amp or caps to backup something in the car.
If you're paranoid about it flip on your headlights for a second, they will kill any power left in the car instantly.

If that doesn't solve it you have a problem with the O2 or the wiring to the heater portion of the O2.

 

yeah, it's still on.. i'll be taking it to someone tomorrow..

 

Code 41 is the oxygen sensor. You might need to recheck the harness and the wiring. But If you reset the ecm and it still comes on it's either something in your wiring or it's something in the ecm

 

i have the worst luck with ecm's.. but i check it by using it on my friend's car and it works fine with no cel... so it must be the wiring.. i hate wiring.