downpipe problem,help!!!
 

my car is a 99 sti typeR.the previous owner cut the downpipe short and welded a stainless centre and backbox to it which is cracked in about 4 places ie its f****d,i got another downpipe from a 96 RA and an h&s centre/nur spec back all bolt on,the problem is with the sensor thats in the downpipe.On my 99 spec its at the top of the downpipe just after the turbo and has 3 wires but on the other one its at the bottom and only has 2,any advice as to what i can do dont want to run without the sensor plugged in....if it will even run,its booked in on wednesday :(

The two wire sensor is probably a cat on fire sensor, and it is not necessary to connect it up. You need somewhere to put your lambda though, I have no idea if the cat on fire sensor is the same size thread as a lambda sensor, but I would have a look. Otherwise you will probably need another downpipe with the correct lambda thread in.

OK, depending on exactly what you've ended up with there, it sounds to me like you're possibly getting 2 different sensors mixed up due the different mounting locations.

The Lambda sensor from your 99 D/P should be at the top after the turbo. I suspect the D/P you have is from a much earlier car than that where the Lambda sensor would have been carried in the headers, (pre up-pipe).

That age down pipe (early) would also have a cat overheat sensor in the very bottom bend o the D/P, I suspect this is the one you're now referring to?


If you already have it fitted, you're gonna need to either change it to a later D/P to carry your Lambda sensor, or weld a new lambda sensor carrier onto the new (old style) D/P.

I hope I read that right and that it made sense?

yeah i understood that,so it means im screwed then and need another downpipe from a later spec car :(

had a look and its different thread the lambda is much thicker plus the wire wouldnt stretch to the bottom of the downpipe,dont want to lose the cat for emmisions reasons and if i decat it would upset the ecu and need a remap so i been told

i have a cat downpipe just removed from a 98 classic will fit yours no probs perfect condition yours for 30.00 if its of any help to you

where are you based,sounds good to me.