warranty?

[starrdaddy]

I was wondering how picky dealerships are about aftermarket stuff. I have an 04.5 LLY with 17k on her. I have an AFE stage 2, and a 4 inch turbo back with cat and muffler gone. 2 days ago it started running rough at idle.standing behind it, when it does it, it sounds like it is "missing".I havent noticed any decrease in fuel milage, and it only does it every once in a while. The fuel filter was just changed 1200 miles ago.please tell me what to do.

[More Power]

Unless you are getting an EGR or MAF code, your dealer shouldn't throw a hissy over the AFE/4" exhaust.

Technically, your dealer can't deny warranty coverage unless they can show that your aftermarket product caused or contributed to a covered failure.

An excessively oiled air filter element could contaminate the MAF sensor, and produce a code. This can be easily rectified by cleaning the sensor with an oil-free automotive solvent (like carb cleaner). And, I'd heard that some free-flowing exhaust systems (especially if the cat is removed) can induce an EGR code.

However, I doubt the above is affecting the idle smoothness of your engine.

Does it idle more rough when cold, then smooth when warm, or rough all the time?

MP

[starrdaddy]

It only seems to do it when it is cold.

[pgreen]

From my experience, dealers will "see" what they want to see. If they really don't want to "see" aftermarket stuff, they won't. Some aren't as easy to work with though. So, the answer is...depends... :D

P

[More Power]

Could the cooler weather have any effect on the idle roughness you're reporting?

The Duramax's I've been around all idle smoother when warmed up a bit. Cooler weather prolongs the amount and degree of roughness after a cold start. After an overnight low of about -4, I started my LB7 about noon today, when the temp had moderated to about 18. Without being plugged in, the engine stumbled a bit after a somewhat longer crank cycle, then idled a little rough for about 30 seconds. Considering the temp, it's all normal.

MP