I have replaced wire,plugs, and coil still shows code for misfire # 3 cylinder what can I check next.

 

http://www.obd-codes.com/p0303

 

Welcome to DF
Did you have this problem for you replace the plugs and wires. If it didn't trace back to what you did.

 

I had this problem before I replaced plugs,wires, and coil. Any advise would be a big help.

Thanks

 

Took to auto-zone showed misfire on #3 cylinder changed coil, wires, and plugs no change. Then changed map sensor had a little change but still not running right. Has 99500 on it anyone have an idea. Thanks

 

took to auto-zone showed misfire #3 cylinder and upstream o2 sensor. Replaced plugs,wires and coil no change. Replaced o2 sensor and map sensor changed some still idles little ruff but not as bad as before.
Anyone have an idea. Thanks.

 

Well, Autozone got THEIR money out of you. The sole reason they offer the scan service in the first place. And I bet you just thought they were being nice. They don't give a crap if you fix it or not...they're hoping you just throw some parts at it. If those don't work come back and buy more parts. That's one hell of a return on a 20 dollar code reader isn't it?

Many, many reasons for a misfire. From what i'm reading you have a wiring issue with your O2 sensor and thats causing the misfire. But.....you never know. It's OK if you don't have any diagnostic equipment or capability. At least go pay a meager diagnostic fee to get the right answer next time and you can do the parts yourself. You'll come out ahead.

 

Cycle the key from off to on/run X3 leaving it in on/run (not start). Now read the codes displayed on the odometer. Should start with a "P" then 4 digits. After changing the parts do you still have codes?

 

Have you read "Causes" in the link in post #2?

Before you changed the parts did you confirm no spark at #3? If that cylinder is getting spark is it also getting fuel and compression? Test the injector and/or do a compression check.

 

Try this because it will only cost a roll of tape. Open the wire harness near the p/s reservoir, you may find some wires that melted.