Having engine issues

The car has been idleing funny and I have to keep the rpms up so it doesn't start jerking. Ok so I took my car to autozone to get the check engine like checked out. It said some emission control thing was messed up (but the dealer told me it didn't matter in arkansas), the o2 sensor was bad, and misfire in cylinder one. First off I bought new plugs and tried em out. The car ran awsome. NO more bad idleing and ran strong. About three weeks later it come back. I then replaced the o2 sensor thinking maybe it has something to do with it. I started it up and ran like crap still. Then I thought maybe the bad o2 sensor was messing the plugs up cause i read that it controls the voltage or something. Went and bought new plugs. Put em in and it still runs like shit. Any ideas? Has anyone ever heard of anything like this?

try having the auto place clear your fault codes and then see if the problems resurface

Then I thought maybe the bad o2 sensor was messing the plugs up cause i read that it controls the voltage or something. Went and bought new plugs.


The O2 sensor does not control the voltage to the spark plugs. The O2 sensor actually determines the amount of unused oxygen in the exhaust gasses . This information, which is in the form of a voltage, is relayed to the ECU which determines (based on a rich or lean condition) how much fuel to add (It doesn't work this way at WOT, but that's another story).


With that said, did you replace the front or rear O2 sensor? The ECU only uses the front O2 to determine the amount of fuel to add, the rear is only used to see if the cat is working and has nothing to do with engine operation.

I replaced the front o2 sensor. I put new plug wires in tonight and it seemed to run fine again. Maybe thats all it needed. Thanks for the help

when you pulled the plug wires was there any oil on them? my gs had this erratic idle like that and it turned out the #3 spark plug/valve cover gasket leaked and fouled that plug, easy fix though.

If changing plugs fixed it the first time, I would keep going down that road. Its not uncommon for a weak wire to cause a plug to go shitty over time. You replace the plugs, it works, but that plugs craps out over time again. Do the plugs and wires this time, and make sure you gap the plugs properly. I can't tell you what the gap should be, since I have no idea what kind of car you drive, and my crystal ball is the shop getting some upgrades done...

what he's saying is put your make, model, year, and tranny type in you sig so people know how to help you. Do this now