This weekend I installed my longtubes and built my true duals. Car sounds great but now I've developed a misfire. Whenever I was taking my passenger side O2 out i happened to break it in half, but it didn't come completely apart. Its hard to explain but its definitly broken. I did a few searches about misfires and read that a failing/ruined O2 can cause a misfire, do you think this is my problem?

Car seems to stumble throughout the RPM range. Also deleted the EGR and AIR systems with the headers. Thanks.

 

The O'2 are important part of the computer setting fuel mixtures. I would replace it right away.

 

I would give your plugs and wires a quick checkover as well.

 

The O2 sensor relies on the tiny voltage developed on the zirconium membrane that separates the exhaust gas on one side and fresh air on the other side. If the sensor is cracked, its very likely you have totally destroyed it.

 

Thanks Injuneer and GTP, FWIW I put on new plugs and wires whenever I did the header install, so I hope they aren't the problem. Can I unplug my O2 sensors and run the car? Will it default to some sort of safe mode so I can see if that cures the misfire?

 

It will run in open loop if you disconnect the O2 sensors. That eliminates the ECM's ability to enter closed loop, and adjust the A/F ratio based on feedback from the O2 sensors. If you have a damaged O2 sensor, it will probably run better with the sensors disconnected. Pull the "PCM BAT" fuse for 30 seconds to clear the ECM's long term fuel corrections, which may be screwed up if a sensor was defective.

 

I bent the casing on my drivers side front O2, and while it "looked" ok it was blowing the engine sensor fuse. Once I took it out, and opened it up, it was easy to see how even a slight tweak of the sensor could short it out; the heating element wires don't have insulated connectors, so its very easy for them to touch the side of the case.

 

I have a 93, they don't have heated O2 sensors.

I got the problem fixed, the new plugs i put in were gapped wrong. Took them out and regapped them to .05, fixed it right up.

I still replaced that oxygen sensor just to be safe.