i put on my new dynomax catalytic convertor and dynomax cat-back. I love it but just on friday, i noticed a weird rattling coming from the exhaust. Earlier today I got underneith the car and retightened all the clamps and hangers. I still rattles, but i noticed if i put my hand on the catalytic convertor the rattling stops mostly. I was wondering if anyone has had this same problem and what they have done to fix it. Also the dynomax convertor is a 3 way, should i uncap the air inlet or leave it capped, since the original cat didnt have and air inlet. Thanx in advance

 

No, you can leave it capped. The cat "can" function as a 2 or 3-way, depending on the car you put it in. That's why the tube is there at all. But I had called and asked about this (I thought they sent the wrong one), and they told me it's the right one, and leave it capped.

Is the hanger at the rear of the catalytic convertor rattling? On my car, for some reason, after putting in a new Y-pipe, the whole exhaust got shoved 1.5" back, and the hanger piece on the cat vibrates against the hanger piece on the trans tailshaft. A screwdriver fixed that!

Also check the heat sheild above the cat, and above the muffler/I-pipe by the axle. Maybe because of the extra vibes of the exhaust system, you're finding a rattle elsewhere- and by putting your hand on the exhaust, you stop the exhaust from vib'ing, and that stops the rattle indirectly.

Also see if the I-pipe is resting on the axle at all, or is getting belted around by the driveshaft.

 

i tried all that, and it didnt do anything. I might try calling jegs and seeing if they will let me exchange it for a new one. Does anyone else have any ideas?

 

That is good to know b/c my tube that runs down to the Converter is broke and of course GM stopped making it. So whenever I put my new converter on I will leave the cap on until I find a good tube. If I can ever find those @#$%* exhaust picese I need so I can put my whole system on.