Noise during exceleration

I have and 08 G6 GT no engine lights are on belts r new and tight. There is a high pitch noise only during exceleration. Sound like coming from underneath car. Could this be a problem with air filter or muffler. Driving me crazy. I have taken it to a few mom and pop shops they dont know. Was going to have it hooked upto make sure no emission problem but they said no engine light computer will not pick up anything.


I would greatly appreciate anyones help!!!:eek7:


PLEASE PLEASE PLEASE

With the engine running block the exhaust (it can be hot so be careful). Does the noise appear?

It sounds like it could be the catalytic converter? There is a post at top of G6 thread that indicated the warranty was extended by GM to 10 yrs , 120,000 miles. I can also confirm this.
My son's 06 G6 with a 3.5 had a rattle sound by engine / exhaust. It was checked at dealership, since dad's self service :) was 1,400 miles away. They found the front converter plugging up with 70,000. Replaced under warranty with no cost.
This is a possiblity for you also. Here is to hoping you find and fix your problem. Good luck