Ok here it goes, I hope someone can help. My wife has a 04 malibu, 2 months ago I replaces the muffler and last week I started getting a rumbling noise coming from the resonator. Which started after the car suddenly stalled and then the rpm's started going all funny. So yesterday I replaced the resonator and the flex pipe, all were direct replacement, not universal, but it didn't change the sound AT ALL, so my question is could the catalytic converter be causing this noise?
Yep. The internals of the catalytic converter came loose and most liely are rattling around. It may of also been the cause of the stalling.. AKA clogged CAT!!!
That's the thing the nothing is loose in the cat, I know this cause I had to take the manifold/cat off (one piece). And the noise is coming from the resonator, I know this cause I put my ear right up to it and that's where its coming from
I'm wondering if its the heat sheild then. That's litereally the only thing left down there to rattle. If you live near chicago, I have a 05 Malibu Classic you can come and get that off of
lol
Turns out it was a defective resonator
