hi ,just purchased a decat pipe for my93 impreza wrx jap import can any one tell me what the sensor is on the original down pipe , it is fitted just after the cat because the decat pipe has no fitting for this sensor also where is the lamda sensor thanks neil

 

The one at the top, near the turbo is the lamda sensor. The one at the bottom towards the center section, is the cat temperature sensor I think. Obviously this one isn't needed if you remove the cat.

 

there is no sensor near the turbo ?

 

one end of the downpipe connects to the rest of the exhaust system, the other end bolts onto the turbo. the lamda sensor is the one at the turbo end.

 

where the down pipe connects to the turbo there is no hole for a sensor on the standard down pipe could it be in the manifold ?

 

Your lamba sensor is bolted to your exhaust manifold/headers. RH side
If your new decat downpipe has not got any additional holes (lamba etc) then dont worry about it to much. You can leave your standard lamba sensor were it is, in the headers. Most decat dp have a threaded hole/nut nearest the turbo for the lamba sensor, your hasn't?
My lamba was bolted into the headers, I removed it from there & place it in the decat dp instead, just makes it easier to access later. I then place a bolt in the original lamba hole (headers).
As for the extra sensor which is fitted further down the original catted dp, I just removed it.