Cyberpunky

I am just wondering if a blocked cat could be stopping my car from getting any real boost. Without going into the countless problems and things I have replaced, my car was backfiring really badly prior to current work I have done and am thinking this bad back firing may have caused a blockage/damage to cat ?

Also what size cat is used 2" or 2.5" ? I am looking at a magnaflow 200 cell Hi-flo as a replacement
TIA

fejjj

Bruce,

I had a problem a while back where I was only seeing 1.2 bar on the stock boost gauge and it my case it turned out to be a clogged cat.

Can't help you in terms of your size question.

Cyberpunky

Cheers Fejjj. I originally was thinking backfires could have caused an exhaust leak, as they were quite violent at times, but Cat being damaged also makes sense.

Paulyy

2.5"

do you want a cat? or do you want option B that also came out with the 944 turbo.

I have that section with out a cat, but with a resonator (factory).. The only thing is, that it's modified so it had no wastegate tie in.

audisport

Absolutely any exhaust obstruction can cause a reduction in boost. My old Audi with a 1.8T had the cat core blow apart and go fully down the exhaust and block in the rear muffler. So make sure you check the whole exhaust if/when you pull the cat.

Cyberpunky

Thanks for the tip as didn't even think of that

Cyberpunky

Car is in getting new Cat now. Turns out PO had put a 3" cat in. Can't wait to get her back

Paulyy

Nice way to get more flow out of a cat.

Cyberpunky

Fixed! Cat had blown out and was blocked past where other pipe ties in. The asthma is gone and she breathing freely again :-D

Paulyy

So there's boost??

Cyberpunky

Car was cold and only drove it about 200m so couldn't check boost but feels like it is revving freely