Ok, so awhile ago I get CEL For cat, finaly I notice i'm losing power so I stopped driving for awhile, I get a HFC from labree. The other day I get everything apart and am installing it only to find it doesn't fit. I call him, assures me it bolts to the stock dp. I measure it and he realizes he welded a nissan flange to it so I have to wait to F***ing weeks to get the right one. Well I just knocked the piece that was clogging my cat out and bolted it back on for now. It runs a bit better but NO boost. Finaly I hear a leak but can't pin point it. I'm only boosting around 5lbs and it sucks. What are some common leak points or could it just be anything. Oh and anyone with a HFC notice any differance with a stock exhaust? (custom 2.5 coming in the next few weeks)

 

The stock cat from a 1.8T IS a high flow cat. Why replace it with some offbeat welded frankenstein? You probably wont notice a difference unless it's 3" and you're BT'd.

A leak in the exhaust after the turbo won't create a low boost situation; it sounds like you have another issue. All you can do is check the hoses and vacuum lines.

 

Yea, I know a leak in the exhaust won't do that, just worded it wrong. So today I hooked up a boost tester and pressurized the intake. The only place thats leaking air that I can hear is through the oil cap. Could a waste gate or that pressure regulator on the intake tube have anything to do with this?