Ford Focus and P0302

[Fudged Undies]

Did an oil change over the weekend(saturday). Spilled a little so I gave the engine a little cleaning. Next day driving the car it hesitates and stumbles after it warms up. Bring it back home, read codes, check connections, clear codes. Next day(monday), car is still stumbling but after driving a bit, it seems to clear up. Monday night it comes back. Only code coming up it P0302 #2 Misfire. Have looked at current parts and don't see anything odd or disconnected including vaccuum lines. Cleared the code, but the car continues to hesitate and seems to have no power. Plan on changing plugs and wires for starters (it's time anyhow). Next step will be to check the coil and possibly the injectors.



Anyone have any suggestions or gone through this?



I really hate foci.

 

[Dingo]

Plugs and wires first. If there's still an issue, let us know.

 

[Tom Schindler]

Misfie= bad plug or wire on cylinder number two.



As Dingo said, plugs and wires would be the best choice to start a repair.





Tom

 

[Alan Peters]

Same code I had with brothers focus. Ditto Dingo and Cayman. Issue was solved after new plugs and wires. Runs like a champ now.

 

[scott degroot]

chances are that you got some water down in the hole for the spark plugs, pull the plug wires off of the spark plugs and blow out the wells really good and dry off the wires.

 

[Fudged Undies]

Well, as a prelim result the problem is fixed. Changed out the plugs and wires last night and the misfire is gone. I say prelim because it went away on it's own Monday morning and it came back Monday night.



After the car gets driven around for a day or two I'll be convinced it's fixed. Car hadn't had a tune-up in 75k miles so it was time anyhow.



Thanks all for suggestions. We'll see in the next couple of days.

 

[Fudged Undies]

As I feared. The misfire is back. With the same code. So now I guess the next step is to test the coil and make sure it's firing and then test the injector. Any other ideas/suggestions.

 

[Tom Schindler]

Swap plugs with a different cylinder. See if it still throws the code.



What wires did you use? Is it possible you damemged the wire replacing them?





Tom

 

[Fudged Undies]

Caymen, as posted last time, I did replaced plugs and wires last week. Are you suggesting coincidence and swap as a test.

 

[Fudged Undies]

Well, got a spark tester and tested the #2 wire/coil. No spark. Swapped the coil and the car is running normal again. Maybe the coil was going bad all along. Don't know. Coincidence that when I changed the oil the coil starts acting up. Came out to be close to a $200 oil change. Yeah the oil and plugs/wires needed to be changed but could have done without the $85 coil/tester. At least it's fixed.