"flutter" noise

First post for me and I need some help. I have a 1998 z71 silverado with 54,000 miles on it. I started to notice when I accelerate I can hear a "flutter" noise. When I get up to speed and I let off the gas the sound goes away. Also when I'm at idle I can't hear it. It only happens when I step on the gas. I don't seem to loose power. Any Ideas what it could be? Thanks for the help.

Anyone?

I've got a '99 with the 5.3 and am having a similar problem. From crawling around under the truck and having someone "blip" the trottle, I think a cat is falling apart. The outside looks good (the whole exhaust system) but I hear a flutter or rattle out the tailpipe.

It's a '99, 5.3, 4x4, with 130,000 miles. Also has a Gibson cat back the is in good shape.

Anyone have the answer for sure?

I took my truck in and they found that the exhaust donuts needed to be replaced. They also replaced the 02 sensor. Set me back a few pennies but the sound is gone and it runs great.

I took my truck in and they found that the exhaust donuts needed to be replaced. They also replaced the 02 sensor. Set me back a few pennies but the sound is gone and it runs great.


Thanks, I'll give it a try