I noticed a loud rattle under low accl. i took it in to have it looked at they said i need to replace my cat...I hope gregg can hook it up...i bought mine off him not even 6 months ago...this sucks...what should i do...any sugg....i want this fixed asap

 

Where on the cat was it broken? At the pipe? Or on the bottom?

SuDZ

 

I had the same symptom on mine... My problem was that one of the spot welds on the catalytic heatshield came undone and started to rattle... I just had it rewelded (along with the other spot welds for good measure).

If the noise is from the inside, however, then you will need to replace the catalytic.