Khanes9010

New here and to the honda scene, I just recently picked up a 2000 civic si and have been messing around trying to get it to run correctly. I have a slight missfire and am getting code 41 primary o2 sensor heater. So I replaced the o2 sensor and am still getting the code and still have a slight missfire. I have read several other threads about the missifre issue but I'm starting with what the codes tell me. I have also checked and reset the timeing it was one tooth off. Could I have gotten a faulty o2 sensor or should I start looking in to the ignition side of things?

Former User

Check 7.5A dash fuse 15 and whether the O2 sensor heater element pin in the connector gets battery voltage.

Misfire - when was the last ignition system tune up done?

Khanes9010

I will check the fuses tomorrow and connection. I just picked up the car in this condition about a month ago and was told it had a new disty put on recently. I'm not sure how new it is tho, it doesnt look terribly new. Also this code was pulled with the paperclip and counting the CEL light. I have a basic obd2 scanner but I'm getting no connection. Thank you for the in put and ideas.

redberan1

o2 sensor heater wire should have absolutely nothing to do with the misfire... check the wiring/harness leading back to the first sensor. the first reply has the right idea.

Misfire is more than likely an electrical ignition issue. my guess is that the CEL light is a misfire code. Could be so much more info behind that CEL light, theres probably more than one and my guess is that your fancy little paperclip doesnt tell you that. If you by chance happen to be around the south wisconsin area, you can come over and i'll read it. My scan tool does everything.
Otherwise, go to an advanced auto parts and have them read it. or a dealer, again just to read it. plugs and wires could be your fix, who knows.

Khanes9010

Got it figured out, my new o2 sensor was a dud swapped it out our for another and the cel is gone. As for the misfire, threw a new cap, rotor, plugs and wires at it and it is smooth as can be. Thanks for the suggestions.