2002 3.0 with a little over 100k. auto tranny
So i had noticed some worse than normal gas mileage, also its been idling a little rough sometimes. ive even caught it idling a little high sometimes. Ive been running on steelies recently, so i had been attributing the gas mileage to that. My comparison to how my truck normally feels is a little off because of the different rims/tires.
Well anyways i threw a check engine light yesterday morning. I kinda guessed it was my IAC valve or my Throttle position switch reading to low. which is a problem i have had before which went away with a little cleaning. I pulled the code and it was showing a cylinder 4 misfire.
I havent had any experience with misfires, but what do they feel like. ive noticed a rough idle sometimes, but not really any bucking or anything on the road. I cleared the code yesterday and it hasnt come back on yet (havent done too much driving though). How long would it take the code to show back up? if it doesnt show back up should i not worry about it?
Also i dont have my manual, so which cylinder is # 4 anyways.
Ive been searching and it seems like just about anything can cause this problem. what do you think?
Here is what i have come up with. whats a good order to do this, and which are a waste of time?
- Pull the plug and see how it looks
- vacuum leak maybe (how and where do i check for this)
- plugs and wires (replaced maybe 6k miles ago)
- coil pack?
- TPS sensor and IAC valve?
- clean out throttle body and MAF? (worth the time? cleaned TB not too long ago)