So, from my other thread, I had just replaced my KS and that seemed to help with my MPG, but now my car is back to its old tricks. Im a tad below a half tank and have driven only 142 miles.

A few days ago my CEL came on with a cylinder 6 misfire, and I could feel it. but after a few minutes it went away. Over the next few days it came and went. So yesterday I put a new plug in 6 ad swaped the coil packs with cyc #4 and reset the CEL.

I am still having a misfire but the light isnt back on for me to check of the misfire followed the coil pack or not.

One thing I notice is that when its misfiring if I have the car in neutral and just gun it, once the car hits 5k rpms or so the misfire goes away completely.

Im wondering if maybe a bad injector is to blame????

Here are some things I have done over the past month as a partial tune up.

New plugs, oil change, new filter, new O2 sensor(the one by the cat) replaced one coil pack, new KS. two cans of seafoam.

Do i just need to wait for the CEL to pop back up??

 

no thoughts

 

I'd just wait for the CEL to pop back on. If the misfire has moved to cyl 4, you know it's the coil pack. If not, start looking at the injector or injector o-ring in cyl 6.

 

Either way cyl 4 and 6 the injectors are easy to change. Check the impedance of the injectors. Off the top of my head they should be 10-14ohms.

 

My money's on the injector and/or injector o-ring, but only if it smells like gas in your engine bay OP. I had bad coilpacks before, but never got below 150-160 to be honest. But it doesn't hurt to check I suppose.

Good luck with the diagnosis and let us know what your findings are man.

 

now the misfire is back but the CEL wont come on.

Im thinking of taking the #6 injector out and looking at it, should I see anything?

 

besides, don't go off the gas gauge when computing MPG...the only good way to do it is at each fill up...divide miles driven by gallons in the fill up.

142 miles for just under half a tank doesn't sound that bad...unless it's ALL highway. I get better MPG in my Max using premium than I ever did in my Grand Am...jus' sayin

 

We here is where the confusion starts.

When I originally ran the CEL it said cylinder 6 misfire. So I swapped the coil pack between 6 and 4 to see if the misfire stayed or went. Today it starts acting up and the CEL pops back on. So I am like great now I can run it so see where the misfire went.

Guess what it popped up...............




Cylinder 5????? I cant win