Cylinder misfire & check engine light

[ergalthema]

2003 automatic Vibe with 218k miles. Starting a year or so ago, the car has been occasionally loosing power and the gear shifting feels strange at a particular speed/incline. On the Interstate at 65MPH, it feels fine. The city stop/go is a little weird when accelerating sometimes, but generally feels/sounds fine.

A few months ago, the engine light came on. The shop said it was a cylinder misfire code. Since then, it has went off/on a few times. Always the misfire code.

I feel like I know how to work the gas pedal so that the "weird gear shifting thing" doesn't happen. I put the shifting part in quotes, because I think it might be a symptom of a misfire.

I only drive the car on the weekends. My ex drives it during the week. It's strange to me that, more than once, the check engine light is on as soon as I first start the car on the weekend. She says the light doesn't come when she drove it. Usually the light goes off after I drive it for a while. Then it seems like I pick it up next weekend and the light is back on as soon as I start the car. There have actually been a couple times when she said the light came on while she was driving, but the last two times she said it was off when she last used it.

I don't like feeling that I don't trust her, but it's hard for me to believe that the light isn't coming on at some point while she's driving it. My guess is she doesn't know how to avoid the "weird gear shifting thing" the way I do, and if it happens "hard" enough it causes the misfire code.

I'm going to take the car to the shop again Monday morning, and try to get a thorough diagnosis. At 218k, and a slight oil leak, it's a tough decision to get a full tune up (which I'm guessing is hundreds of dollars).

I basically wanted to explain everything and see if anyone has any guesses or advice. Thank you.

[Salsa Guy]

Post the exact code. You could have a bad Coil.