Freddie

A couple months ago, on a 105-degree day here in LA, I was cruising along the freeway when the dreaded CEL appeared. My car, a 2005 6MT w/ 53K miles, was running perfectly, but not wanting to take any chances I turned around and went straight home. The next morning, since I was almost due for an oil change, I took the car to the local stealership. They changed the oil and pulled the code which they said was for engine misfire. They told me I needed new coils, plugs, and plug wires, which would total just under $800. I pointed out that all those items had been replaced less that 20K miles ago. Their response was something like "Oh well, they're out of warranty now, you'll just have to replace them again".

I paid for the oil change along with a $79 "diagnostic fee", asked them to clear the CEL, and told them I would come back later. I then headed home, thinking I would either replace those parts myself or consider an aftermarket ignition.

The light did not re-appear and the car was still running fine, so a few weeks and a few hundred miles later, I decided to take a road trip to Northern California. Sure enough, about 200 miles into my trip, in the middle of nowhere... "Oh s**t there's the CEL again!". Still the car was running great and I guesstimated to have been getting better than 20 MPG, so I figured it couldn't be misfiring that badly and decided to continue to either Stockton or Sacramento where I could find someplace to again get the code read and figure out what to do.

About 75 miles short of Stockton I stopped for lunch, gas, and to check the oil. Merging back onto the interstate I looked, and lo and behold the light was gone.

The remainder of the trip all was well, no more CEL and I averaged 21.5 MPG over 1135 miles of driving; mostly open road at 75 MPH but with some twisty 2-lanes, hills, and city traffic. I have put on a couple hundred miles more since I got home. Still no more CEL.

Anyone else have a similar story of CEL coming and going? Shouild I be worried?

jasonrxeight

you do know you can go to autozone to get the codes read and cleared for free right?

just replace whatever needs to be replaced, it will come back sooner or later.

new coils are like $2xx and new plugs are like $8x

Freddie

Yeah, I know. The dealer does apply the "diagnostic fee" to any needed repair. I didn't think they would blame coils, plugs, and wires because those were all replaced quite recently.

Well, I sure don't intend to replace all those parts this frequently.

I have gone a few hundred miles more since my original post, still no more CEL, so I will just keep enjoying my car and deal with the light if and when it returns.

pistonhater

It has happened to me - and from what I've researched on the forums - to many others as well: the dreaded "random" misfire CEL. The CEL either flashes fast and then disappears, or stays on regardless.

After reading and reading so many threads on this issue, I'm convinced it's something that just happens randomly in some cars more than others