i just had a magnaflow muffler welded in... now during accel. i hear grinding sometimes... any idea what this could be?

 

have you looked yet ? see if its hitting frame or floor board... ?

 

sounds like muffler bearings going out! haha, no my jeep does the same thing. I installed a glass pack, and it was a little to long, so the tail pipe will vibrate against the bottom of the body, and make all kinds of nose.. it drove me crazy.. so i did some bending and it doesn't do it anymore.

 

x2 on the muffler bearings you cant reuse those. Sounds like the rubbing on the body to me.

 

muffler courner COULD be hitting the u joint or driveshaft when you accell from the motor torqueing, mine did that when I first put the new muffler on, then i re adjusted it

 

proballly something rubbing......get under there and shake the exhaust. or take it back to whoever worked on it......

 

I would tend to agree with a poor installation and it's rubbing somewhere. No issues with our DIY Magnaflow install.