2002 4.6L Puzzler

[jdorff]

I have a gunmetal '02 with about 100000 miles on it. Recently, especially in the cold weather since December, its seemed to be having some tuning issues? After starting, it seems to be running a little softer than usual, and the exhaust is quieter and kind of muffled. It doesn't flutter or cough or show any other signs that somethings off, it's just like a quieter version. This happens about 60 or 70 percent of the time now, but it varies from start to start. It will either have that edge to it or it'll sound off, it doesn't change while running. I'm thinking maybe an air flow sensor is getting bad readings and telling the comp to change the fuel mixture? It just doesn't seem to be anything mechanical based on when and whats been happening. Im stumped so any thoughts would be much appreciated.

Thanks guys!

 

[BurningRubber]

No power loss or anything? After a cold start especially during cold weather, the exhaust will "quiet" down once the engine is up to temp. At least at idle, anyway. This isn't as noticeable in the warm weather because the engine isn't trying as hard to warm up.