l67 cats. quick question

**CHA53R** · 21-10-2011, 10:17 AM

Are the stock l67 cats the same size? Mine has 2 different sized cats. One with heat shield ( smaller) one without ( larger) think it's the smaller one making my exhaust sound really tinny.

**cander24** · 21-10-2011, 10:43 AM

Should both be the same size if stock. Probably had one replaced in the past due to collapsed internals?
Cheers

**blacknight** · 21-10-2011, 02:55 PM

I had to replace both cats even if one was stuffed as the exhaust tech said the engine wont 'breathe' properly. What would the effect be when one cat is smaller than the other?

**pjdm1980** · 21-10-2011, 03:24 PM

Yer one of my cats was shot and........

Oh my bad wrong topic!!!!!!

**Not_An_Abba_Fan** · 21-10-2011, 03:35 PM

Funny how the exhaust guy said you had to replace both because of "breathing" issues then proceeds to fit two different sized cats.....

No, they won't really have any affect as long as they both have the same flow rating. Which standard ceramic cats do, they are all the same. Unluss one of your cats is high flow, it shouldn't make a difference to note.

**CHA53R** · 21-10-2011, 04:33 PM

Mine are 2 complete different cats. The smaller one sounds ratsh/t would I have to replace both? Or should I just go high flows? Here's a few pics in order drivers small, passenger larger then both from front. Larger says AC smaller says cat and a series of numbers