2k05gt

I hit MIR a few weeks back for the first time this year, and my last run of the day I went past the trap and let off the gas and a huge puff of white smoke came from the exhaust. Now I hear a misfire while at idle or on cruise control at low RPM, it happens every 2-5 seconds and at idle like waiting at a stop light I can feel the car shake, you can hear the tone of the engine drop when that happens. At WOT you can here a constant misfire sounds like popping.

I went to a local 1/8 mile track a week later with no issues other than it misfiring.

. What could this be? could it be a serious problem?

I thought Plugs but I pulled them and they look fine, I cleaned the TB and MAF sensor, nothing helps.

here are the plugs, they look good 46,893 miles


I did use 2 Gal of 104 with 1/2 tank 93 oct.that was over 3 months old (the car sat over the winter while I installed headers and polished the Valve covers)

I also reloaded the tune just to see if that would fix it, but nothing...

Any Ideas, other things I can try?

MD07gtcs

Not sure what the problem is but I would say by looking at the picture of your plugs that one of those plugs does not look like the others. Good luck

hammeron

hey 2k05gt, are there any trouble
codes?

moosestang

Replace the plugs and hope that is it. The first plug in your pic looks different from all the others. What is all over the threads?

aclass

Actually the first plug looks cracked. But whether it's cracked or not, that appears to be the cylinder that is dead.

07 GT/CS

I actually had an experience kinda like that with my old F-150 5.4l Mod engine. I replaced the plugs and it seemed to keep on fouling out the same plug. In the end I took it to a shop andit turned out I had a bad cop (Coil Over Plug). Hope this helps andgood luck.

07BOSSGT_S197

I had the exact same problem. Tune was "so-so" and the plugs were bad. Try a new set of plugs and see where that gets ya. Takes care of part of the tune-up and a cheaper diagnostic.

p.r gt

check the cop i had that problem too.

jdback19

Change your plugs and problem solved my car does this about every week........ .

2k05gt

whaaa...
Every week, These damn plugs cost 11.98 each plus tax the 100 bucks wow.
I ordered the HT1 do you have to use the HT0? I assume you are turbo charged...