Replacing stock exhaust on an EGI.

[Chonker]

Alright guys and girls, I\'ve managed to get my mitts on a stainless exhaust from these forums. Was gonna start fitting it the other day when I noticed the stock cat has a small pipe which runs from the side of the cat back up to the engine. So you have the main pipe which runs from the engine to the back of the car, but also a side pipe which goes from the engine (I think) to the cat. The new exhaust decat pipe doesn\'t have anywhere for this to go? Any ideas how to proceed? I was thinking it could be the lambda sensor or an gas intake valve to recycle the exhaust gases but either way. Wasn\'t comfortable with just bypassing it without checking on here first.

Any advice would help.

Thanks in advance, will.

[dthebuk]

this pipe takes air from the intake and pumps it into the cat for the sake of emissions. Removing this air pump free\'s up a fair bit of power. if you search for air pump removal there should be a guide. I\'ve never done it, but a couple of people have had idle issues afterwards.

The difference between running an air pump and not is night and day

[Brett]

Upgrading the exhaust on the Egi is not exactly a simple affair if you intend to remove the air injection as well.
The primary thermal reactor has direct air injection, and the downpipe has co-axial flow. The air from the pump (as you have discovered) is then fed into the secondary thermal reactor halfway down the car. (the egi has no CAT)

What parts do you have in this stainless system? Is it a complete system including headers? (to get the most from the Egi you should remove the primary thermal reactor and fit a 2-1 header.

:wave

[Chonker]

Hi thanks for the advice so far guys. I\'ve got the Decat pipe, the y-piece and two back boxes. So I was going to (for the moment at least only replace them. From what you guys have said so far I am thinking of leaving the air pump in place and just using some hose clips to secure it underneath the car. I don\'t really want to do something could affect the idling. Plus I want to leave everything else in place in case it fails emissions during the mot. That way all I have to do is replace the heat exchanger (rings a bell you saying that, think I\'ve read about that before).
So, do you think just just fitting the exhaust pieces I\'ve got and just tying that pipe for the air pump to the underneath would be a bad idea or ok?

Thanks again for the advice.

[Brett]

Iirc there is a flange on the split air pipe, so you should be able to remove a large section of it anyway :wave

[Chonker]

Ok, I\'ll go ahead today and do that. See how it goes. Thanks again for the advice
If I run into any probs I\'ll post about them in here.

Cheers, Will.

[Brett]

No probs, hope it went ok? (other than the usual siezed bolts and skinned knuckles)

:wave