Whats the sensor in the top of the pipe near the Turbo?
Some say Cat heat sensor some say O2 sensor???

Car is V5 STI.

Thanks

 

its your o2 sensor also known as a lambda sensor

 

Hey bud - If youre talking the sensor after the cat its the "cat on fire" sensor. The lambda sensor is under the engine on the exhaust manifold. If you de-catting then just tie the sensor in question out of the way in the engine bay! Same advice given to me when changed the downpipe - ALL GOOD!!

 

Top of the downpipepipe on a 1999/V5 sti is the lambada sensor- there is a white plug next to your gearbox dipstick that connects to it,if you do not fit it will lead to engine check light coming on.

 

I believe I Stand corrected on this one! apologies - Mine is pre faclift so the cat sensor is there on mine!