91 Golf hesitation and exhaust leak

Hi all,
I have a 91 golf gl. I recently replaced her exhaust with the dual
downpipe system and she was a dream to drive for about a month.
Recently, however, she has begun hesitating on accelerations from idle
and she sounds like an old truck when accelerating (I can hear the
individual cylinder explosions well). Her power has also dropped
significantly.

I think the o2 sensor is fine. I replaced it 10-20k miles ago, there
was a bit of a struggle getting it off the old manifold and it is now
located on the cat. She drove fine for ~1 month so I don't think this
is the problem.

I was under the hood the other day searching for the exhaust leak.
When I turned the throttle the engine would putter down for a second
then rev up like it's supposed to shaking violently. I held my hand
around the manifold/dp area right when I started it up and didn't feel
any puffs, only some slight wisps coming from the dp/cat junction.
I've read a few threads about the flex joint on the dp going bad, my
dp is used but looked in good condition when I put it in.

I'd appreciate any help on resolving this matter.

thanks,
-Matt

I had chunks of catalytic converter break loose and clog my muffler in
my 1984. Exhaust would leak anywhere it could. So it leaked out the
manifold to downpipe. It sounded like a saxophone or kazoo under the
hood as exhaust passed by the metal gasket. Maybe your converter has
fallen apart. Blocked exhaust will cause acceleration problems.

On Sun, 5 Oct 2008 07:26:38 -0700 (PDT), MasterChifa DeleteThis @gmail.com wrote:

>Hi all,
>I have a 91 golf gl. I recently replaced her exhaust with the dual
>downpipe system and she was a dream to drive for about a month.
>Recently, however, she has begun hesitating on accelerations from idle
>and she sounds like an old truck when accelerating (I can hear the
>individual cylinder explosions well). Her power has also dropped
>significantly.
>
>I think the o2 sensor is fine. I replaced it 10-20k miles ago, there
>was a bit of a struggle getting it off the old manifold and it is now
>located on the cat. She drove fine for ~1 month so I don't think this
>is the problem.
>
>I was under the hood the other day searching for the exhaust leak.
>When I turned the throttle the engine would putter down for a second
>then rev up like it's supposed to shaking violently. I held my hand
>around the manifold/dp area right when I started it up and didn't feel
>any puffs, only some slight wisps coming from the dp/cat junction.
>I've read a few threads about the flex joint on the dp going bad, my
>dp is used but looked in good condition when I put it in.
>
>I'd appreciate any help on resolving this matter.
>
>thanks,
>-Matt