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Cat Bypass
Posted: Fri May 14, 2004 7:33 pm
by 2hot4u
Hi guys, anyone know of a cat bypass for the gti that incorporates the lambda sensor????
Final managed to get my car through its MOT so thought now is a good time to get the bypass.
Posted: Fri May 14, 2004 11:15 pm
by KarlM
best to speak to Powerflow, they can make one up
Posted: Sat May 15, 2004 2:42 pm
by gargoil
yeah powerflow done mine!
Posted: Mon May 17, 2004 2:40 pm
by 2hot4u
Does anybody know where abouts the lambda sensor is???? Is it built into the cat itself???? I phoned powerflow up and they said that it wouldnt be possiable to replace the cat if it has a lambdo sensor in it.

Posted: Mon May 17, 2004 6:45 pm
by Josh_PoloGTi
That's a crock.
They have to make up a pipe to replace the cat which has a screw-hole in it for the lamda sensor to scre into.
Muppets @ Powercrap.

Posted: Mon May 17, 2004 7:14 pm
by dubpolo
i'ed stay away from a bypass, my mate had one on his 1.4 rover 200 and it fooked his engin!!! its going to cost him £400 for a new head.
if your going to get one anyway make sure you get a good branch of powerflow, if you live near chester go to Roton
don't go to the one at crew!!!!!!!!!!!!!!
Posted: Mon May 17, 2004 7:15 pm
by dubpolo
you could make one up your self if you know anyone with a welding rig.
Posted: Fri Jun 04, 2004 8:15 pm
by waynesGTI
u should not have a by pass cuz thereis 2 sences on ya car one at the start of the manfold and one after the cat! just so the the ECU knows the cat is working! and it will not know what's going on meening loss of power!
Posted: Fri Jun 04, 2004 11:28 pm
by gargoil
Mate of mine had his tested at 141bhp with full decat and bmc, no power loss there!
Posted: Sat Jun 05, 2004 10:34 pm
by ttaw2
try longlife exhausts, they might be able to sort you out a bipass pipe... In theory your ecu sould be able to adjust to the increased airflow, as long as the bipass incorporates all the correct sensors. Also, it's worth remembering that anything you do will have to be replaced for original every time you need an mot.... My mate from uni in Loughborough used to have a fat black gti, i'm sure he had a bipass pipe installed, i'll try and get hold of him and find out where he got it from..
Posted: Tue Jun 08, 2004 8:48 pm
by 4paws
when i done my gti conversion i got rid of the lambda after the cat as its only there to make sure the cat is working ok, the front is for engine mix etc. the only thing caused by doin away with rear lambda is it brings on the engine light and a fault code but as my 6n dosent have one so no probs then
