how bad do exhaust leaks effect GN's?

[GNJesse]

i found that i have exhaust leak(s) around my exhaust manifolds. i am using the gaskets that came with my rebuild kit but i am going to take it all off and use copper RTV. how bad will the car act up by having a bad exhaust leak here? my car hasnt been real fast and it shows that the car is running lean and sometimes leans out during boost. im just wondering how much having a leak will effect the car so i know what to expect when the leaks are fixed. thanks.

Jesse

 

[FastRegalWE2]

exhaust leaks PRE turbo are quite bad for a couple reasons,
1. that exhaust is supposed to be spooling the turbo
2. fresh air is getting in before the O2 sensor and making bad readings and causing problems with your A/F ratio

you WILL notice quite a big difference once you get the exh leaks fixed

 

[PhilM]

I dont run header gaskets...anywhere... if the flange mill is thick and flat, and the head surface is flat, warping isn't as much of a problem. I've never had probs with exh leaks. Maybe im just lucky though

Phil

 

[Bonden]

If you have leaks at the headers, you are gonna love it when the leaks are gone...it's been a recent experience for me

HTH

 

[VadersV6]

It throws off o2 readings and hurts mileage. I had a cracked drivers side header and replaced it, but there was really no difference in spool up, mileage, etc. Last weekend I found that the compressor collector gasket was either wrong, or the backpressure was so high that it pushed a big area of the copper gasket out of the flange and allowed alot of air to get in and smack right onto the o2 sensor. I replaced it with a generic 2.5" header collector gasket (they didnt have the real gasket), and my mileage seems to have improved a little. The most drastic change however, was that I was able to move my BLM correction factor (with my extender chip) from 1 all the way to 4. The default number is 8, but I had to bring it down to 1 originally cause I was running so rich at idle. Now its not nearly as far off.

 

[PaCemkr86]

picked up 3 tenths at the track, by fixing the leaking drivers side header

 

[turbo john FL]

i am having a simular problem . driver side manifold leak replaced the gasket with a copper one and it still leaks . any better choices for gaskets to use or ones that anyone has had better experiances with

 

[PhilM]

I dont get it... I have stock headers that I surfaced and they dont leak... same story for the turbo flange...

Phil