Cat bypass(?) attachment
Thread Starter
Race Car
Joined: Nov 2001
Posts: 4,140
Likes: 1
From: Surrey, UK
Cat bypass(?) attachment
Hi,
I took my engine undertray off at the weekend and this was my first chance to see the bottom of the engine. One thing surprised me a bit.
Part of the exhaust system is a pipe at the back of the engine (by back I mean nearest the rear of the car) running parallel with the bumper (and it's just in front of the bumper). I assume that this is my cat bypass?
My question is on how this is attached to the rest of the exhaust system. It looks almost like this pipe was not long enough - where it is joined to the main system there is about 4" of a think orange / brown colour rubbery material. This is attached to the end of each pipe to complete the join and is held onto each with a jubilee clip. As far as I could tell there was nothing solid behind it - it seems like the pipe at the back is simply too short and the gap has been made up by this stuff. The pipe itself seems solidly enough fitted so I assume it's attached elsewhere.
Is this normal? It didn't really look like Porsche quality fitting to me and I begin to wonder if the fitting was a bit of a bodge job. I've posted another thread today on idle problems when the car first starts which began when my cat bypass was fitted. If this pipe is the bypass pipe then I wonder if these problems started because the bypass pipe doesn't really fit the car.
Dave
90 C4
I took my engine undertray off at the weekend and this was my first chance to see the bottom of the engine. One thing surprised me a bit.
Part of the exhaust system is a pipe at the back of the engine (by back I mean nearest the rear of the car) running parallel with the bumper (and it's just in front of the bumper). I assume that this is my cat bypass?
My question is on how this is attached to the rest of the exhaust system. It looks almost like this pipe was not long enough - where it is joined to the main system there is about 4" of a think orange / brown colour rubbery material. This is attached to the end of each pipe to complete the join and is held onto each with a jubilee clip. As far as I could tell there was nothing solid behind it - it seems like the pipe at the back is simply too short and the gap has been made up by this stuff. The pipe itself seems solidly enough fitted so I assume it's attached elsewhere.
Is this normal? It didn't really look like Porsche quality fitting to me and I begin to wonder if the fitting was a bit of a bodge job. I've posted another thread today on idle problems when the car first starts which began when my cat bypass was fitted. If this pipe is the bypass pipe then I wonder if these problems started because the bypass pipe doesn't really fit the car.
Dave
90 C4
Race Car
Joined: Jun 2001
Posts: 3,706
Likes: 10
From: Virginia Beach, Va.
Sounds to me like you're referring to your heater pipes, they're aluminum and attached to your heat exchanger "heater boxes" via @4" orange "rubber-like" connectors...as you described them.
Directly behind this should be your PRIMARY muffler, and on the left side of the vehicle should be your catalytic converter...if it is bypassed, you will see either a straight piece of pipe with just a "boss" welded in for your O2 sensor or a "premuffler" of sort in place of it.
On the right hand side, opposite your catalytic converter is your SECONDARY muffler, it should have the final exhaust tip attached to it and have the inlet located very near where the tip is attached.
This, is how things should be situated/look if you have factory exhaust.
Again, I believe the pipe running parallel to the bumper with the orange connectors you're describing is your "heater pipes" - dunno the correct nomenclature for these! If you look, you will see a third inlet for this pipe, a larger one, coming down from the left hand side of your engine compartment...follow it upwards and it will turn into the black plastic ducting attached to your heater blower motor.
They provide fresh air taken in from the blower motor on the left hand side of your engine compartment and direct the air thru your heat exchanger "heater boxes" to heat up the air for your cabin.
Hope this all makes sense, it's late, I'm tired...and STILL stuck at work!
Directly behind this should be your PRIMARY muffler, and on the left side of the vehicle should be your catalytic converter...if it is bypassed, you will see either a straight piece of pipe with just a "boss" welded in for your O2 sensor or a "premuffler" of sort in place of it.
On the right hand side, opposite your catalytic converter is your SECONDARY muffler, it should have the final exhaust tip attached to it and have the inlet located very near where the tip is attached.
This, is how things should be situated/look if you have factory exhaust.
Again, I believe the pipe running parallel to the bumper with the orange connectors you're describing is your "heater pipes" - dunno the correct nomenclature for these! If you look, you will see a third inlet for this pipe, a larger one, coming down from the left hand side of your engine compartment...follow it upwards and it will turn into the black plastic ducting attached to your heater blower motor.
They provide fresh air taken in from the blower motor on the left hand side of your engine compartment and direct the air thru your heat exchanger "heater boxes" to heat up the air for your cabin.
Hope this all makes sense, it's late, I'm tired...and STILL stuck at work!