A few days ago, i pulled to a stop and my cars idle was bouncing up and down a few hundered rpm's. the check engine light was flashing then stayed on, i shut off the car, started it agian, same thing with the idle, shut it off agian, then poped the hood, checked the fluids, all good, started it agian, ran fine, but the check engine light still on. started my car this morning, check engine light was off. After normal driving for a while pulled to a stop sign, bouncing idle agian and check engine light was flashing, but i just kept going, it cleared up and the light didnt stay on. i brought it to a shop and error codes for a miss fire came up. when it first did it i thought it was a broken vacume hose, but when it went away that couldnt be it. what would be the next thing to check? i was reading about it could be a mass flow air sensor or a coil pack. how can i check to see if its these parts that are misfunctioning, thanks for any help

 

if ur car is having those problems its the coilpacks. Easiest way to check is to scan the car and see which cylinder is misfiring. Then go swap the coil packs into different cylidners and see which one is misfiring after a new scan. That will let u know which is bad.

 

it was a vac leak, if it was a coil pack it would be misfiring a lot more than it did, but thanks for the reply