99 a4 1.8tqt

Exhaust leak at Flange/cat

Because of the leak I can hear the turbo pretty easily. It starts spooling up as soon as I step on the gas. Boost hits around 5-7 psi and vac goes as low as 30 while driving. I've got a CEL throwin p1136 (too lean?) im assuming thats from the exhaust leak. Any idea why the turbo's spooling up this much?

 

Well being that the turbine wheel is driven by exhaust gas, it spins whenever the motor is running. All the boost/vac lines, the N75, and the DV/wastegate are what control how much boost actually makes it into the intake mani. Your boost/vac numbers sound right, maybe you're just hearing it more now than you did before because of the leak?

 

so this should be fine then? I'm replacing my DV this coming weekend with a 710n and then hopefully getting a custom exhaust this weekend as well... we'll see.

 

30 is a really low vac number, IMO.

 

I thought it was a bit low too, i usually run about 22 at idle, ~25-26 when coasting at speed, but never lower than that. I've never heard of TOO much vacuum before have you?

 

Too much vacuum? I guess it just means you car "sucks" a lot lol

 

haha 30 is not a lower vacuum, its a higher vacuum and i idle at like 22-24ish depending on the temp of the car and outside temps and if any of the aux stuff like a/c or whatever is running and every once in a while ill get 30 out of it when coasting in gear.

 

yea those are closer to my actual numbers. I dont think i've ever actually seen it hit 30. Idle around 24 and get 26-28 coasting. Around 2k i'm at 0 though...

 

Maybe it cause I have tip, but when in park im at 20, in gear im at 15, and itll drop to about 25 (temporarily) when i let off the throttle at cruising speeds

 

i'll take it for a ride today and get the exact numbers for you.