Problem with rattling undercarriage (bottomed out)
 

Hello,
so after a lot of research and the opinion of many Cobalt owners I was told I need a new resonator.

Just to make sure, I uploaded the video of the rattling to YouTube so you can take a look. The noise comes from inside the "resonator". I was told prob when I hit underneath it separated the metal inside from the housing and now it rattles.

My shop guy told me my catalytic converter was bad, but he did a quick lift and I didn't feel like he was sure about it.

Anyways, I need to replace the resonator and I was thinking to get a glasspack to add some good sound and it's only $20.

Question; what size is the piping before/after the resonator in 2.2 balts? I just need to cut it off and weld the glasspack in place, I believe the piping is pretty small. I replaced the muffler with a magnaflow and it was a 2.25" inlet. But I think it's even smaller around the resonator.

Also I'll leave the video here for reference. Thanks in advance!

Thats gonna be crazy loud and sound like ass

Well I still haven't decided which way I'm going, might just replace with a new stock resonator. But I need the measurements. How long is the resonator and what's the piping diameter?

I've seen videos on YouTube and it doesn't sound bad IMO. But to each their own lol

If you replace the resonator with a muffler/glasspack whatever it won't change the sound much, you should be fine.

I'm not certain on the 2.2L but it's probably 2.25" exhaust like the muffler, I would slide under there and check for sure though. Or take it to an exhaust shop and have them replace it, they will put something the right size in and probably won't charge much more than you will spend buying the glasspack yourself.

So after a bit of research I'm not sure its a "resonator" anymore. According to this website this is what I need:

Number #4 (Exhaust pipe)
http://www.gmpartsonline.net/media/i.../C/CL05222.gif

It costs $287 in gmpartsonline but then on eBay they sell a "catback exhaust" that comes with that #4 pipe for $129 shipped.

http://www.ebay.com/itm/GM-CHEVY-COBALT-2-2L-DOHC-STAINLESS-2-25-CATBACK-EXHAUST-PIPE-3-5-MUFFLER-TIP-/391144432618?fits=Model%3ACobalt&hash=item5b120663ea&vxp=mtr
I'm not sure what to do anymore, I don't think I can weld a glasspack onto that pipe because its too near the gasket where you screw it to the cat pipe.

What'd you guys think?

That's the resonator, you can have it cut out and replaced by any competent exhaust shop, or you can buy a full cat-back and replace that and the rest of the exhaust going back to the bumper in one shot.

If I do a cat-back exhaust that gets rid of the muffler right? I just bought a magnaflow muffler thats why it would be a loss for me, and cat back is prob too loud for a stock 2.2 anyways lol
I like the sound I have right now, repairing this would be top choice, if I could just make the muffler a bit deeper (maybe with a glasspack) that would be great.

It will replace the muffler also, yes.

If you add another muffler in place of the stock resonator it will sound the same or possibly quieter depending on what you put in there.

i wouldnt add a muffler inplace of a resonator.
he needs to just find a new stock resonator and just weld it in.