Exhaust Rattle

I just installed my stock muffler back in and it rattles now! It only rattles when in Reverse or Drive at idle. Not when in neutral, driving or when truck fully heats up. The stock muffler has a turndown before the axle. I used all the stock proper hangers. I also only have a heatsheild on cat #2. I took off the 1st cats heatshield back when I had my flowmaster because I had a rattle aswell (didnt solve it). Any ideas?

 

Is it safe to just take the 2nd cats heatshield off? I already took off the 1st cats one off.

 

mine rattles too....i'm fairly certain its the heatshield on the 2nd cat, as its really "tinny" sounding. i'm about to just take thing thing off since my skid covers the majority of it.

 

Still haven't figured it out...

 

did you weld it or use a cupler and exhaust clamps? i had the same problem with my camaro a few years back because i used clamp and a cupler and it wasnt a very tight fit. i just took a die grinder and put about a 1/8" slot on either sime of the pipe and stuck the cupler into it and the clampe fit like a charm, small amount of leakage but nothing too noticable.

 

I welded it....

 

well shit. id say check all of youre hangers, clearances, the manifold flange, all the obvious culprates. could be some debris inside the muffler or cat?

 

But the weird part is it only rattles when it first starts in the morning.

 

in that case, im gonna say i think its the manifold flange. just check those two bolts on each manifold, more often then not they will need to be replaced since they rust relly quick. i could be mistaken but id need to hear it in person to be sure.

 

how long does it take for the rattling to stop once its started? could be expanding from the heat, stopping the rattling.

 

I just fixed a squeaky rattle by installing 7 new grill clips! $15 and my rattle is gone. it would rattle at various different times of the day and night. Hope that might help. good luck, i hate rattles. that's why i own a Tacoma!