[QUOTE=jamesm cossie;5322527]Hello

I'm sure these questions have been asked before but I might be getting a mk2 focus rs fairly soon.

The car im looking at has a full miltek? Turbo back decat exhaust.

The engine warning light is on and the owner said it came on 70 miles after fitting the exhaust due to the decat?

Does this effect running? How do you turn the light off without fitting the standard exhaust back on?

I bought a Lambda Sensor Elbow from Autospecialist and my light has stayed off (touch wood)
Hope this helps