Rough idle after fill-up **Solved**

[CrackerTeg]

Does your car bog down at all?

[fabulous010]

Silver bullet, it probably is just a heat shield around the cat. I had mine rattling after my shop torched the bolts off to install my header. Ended up loosening the upper shield around the cat. So I had that shit ripped out. I would suggest ripping off the shields b4 you go replacing the cat.

[Silver Bullet]

@crackerteg, what do you mean by bog down?

@fabulous010, I hope that's the case. I did run over a parking bump by accident and i bottomed out not too long ago so that could possibly be why...

[CrackerTeg]

From the freedictionary.com:

1.   bog down - get stuck while doing something; "She bogged down many times while she wrote her dissertation"
bog
break off, discontinue, stop, break - prevent completion; "stop the project"; "break off the negotiations"

2.   bog down - cause to get stuck as if in a mire; "The mud mired our cart"
mire
get stuck, grind to a halt, mire, bog down - be unable to move further; "The car bogged down in the sand"

3.   bog down - be unable to move further; "The car bogged down in the sand"
get stuck, grind to a halt, mire
stand still - remain in place; hold still; remain fixed or immobile; "Traffic stood still when the funeral procession passed by"
bog down, mire - cause to get stuck as if in a mire; "The mud mired our cart"

4.   bog down - cause to slow down or get stuck; "The vote would bog down the house"
bog
slow up, slow, slow down - cause to proceed more slowly; "The illness slowed him down"

[Silver Bullet]

Nah my car never bogs down. When I cruise at 45+ there's just a rattling sound coming from underneath the hood.

[CrackerTeg]

Probably a heat shield like Fab said.

[v6sicksspeed]

Resurrected.

Finally got to the bottom of the rattle.  First thing i did was check the heat shield - all seemed fine.  Bolts were tight and not loose.  There is a hanger right in front of the cat though with a rubber mount that seems to hold the cat up.  the rubber went bad and dropped the cat an inch or so which caused it to rattle against the metal bracked instead of being held in place of the rubber.

in a nutshell - easy fix.  glad it wasnt the cat.