Why does an exhaust leak cause performance problems?  Because the Oxygen
Sensor is under reading the output?

Just from a layman's knowledge it would seem as if the faster the exhaust
leaves the engine the better.  Why would an exhaust leak before the muffler
hurt performance?

Paul
----- Original Message -----
From: "Jay L Snyder" <Jay.L.Snyder@USA.DUPONT.COM>
Newsgroups: groupstudy.vanagon
Sent: Monday, November 27, 2000 2:51 PM
Subject: Fix Those Exhaust Leaks!

> I fixed a small leak in my '85 exhaust system.  It was leaking at a
cracked
> weld on the pipe that runs between the y-pipes and the cat.,  ( the pipe
> that has the O2 sensor threaded into it).  The crack was right after the
> y-pipes come together and about 6" before the O2 sensor.  I could hear a
> slight leak, but I didn't know where it was until I was crawling around
and
> I spotted the tell-tale carbon trail.  To make a long story short, it has
> noticeably improved the mid band power and now pulls much more smoothly up
> through second and third gear.  BTW, the part came from the Bus Depot and
> fit perfectly between the existing pieces.  I am guessing the Digijet was
> adding extra fuel to compensate for this leak?
>
>                                                              Jay '85 Westy
>