[cobrastang04]

Hello, I recently purchase a 2004 svt cobra about 2 months ago. When i bought it the car had no key so i didn't know how it ran. I towed it to ford and got a key programmed. Everything seemed fine until I noticed it idled kind of rough. I noticed it had a steeda 2.81 sc pulley and idler. I have no check engine light. I decided to remove the plugs and found that the porcelain seemed melted or overheated on most of the plugs. I decided to replace the motorcraft plugs for ngk tr6's. When i started the car it ran great. After driving for a few days I'm noticing the car idling a little rough again but not as bad. I havent removed the plugs but I'm almost positive it can be the same problem. Can anyone help? I'm wondering if maybe it was never tuned for the new pulley or do i have the wrong plugs? The motor only has 28k on it! What should i do?

[stevew01]

sounds like you might need to run hotter spark plugs, maybe try a double platinum or quad platinum plug. Maybe someone else might have a better idea as what could be causing it.

[Cobrals1eater]

Normally the TR6 plugs are fine. I run them in mine. Try cleaning the mass air meter. If it gets a build up of dirt or oil off of the air filter, it can cause poor idle and driveability problems. I would also get it tuned to make sure everything is where it needs to be.