On a 1995 Sti V Limited, When crusing at 2500 ish Rpm it feels like its Hunting / Holding back a bit,

Whats the normal Cause of this? its not a Ignition missifre its deffo a fueling problem, Was thinking of Lambda sensor (old engine whent Bang big style 3000 miles ago, so no end of **** would have gone in the exhaust) or a Dirty Maf but i am not sure

Oh and its about 15mpg LOL (it is mapped though)

 

I'd change the Lambda/O2 sensor as my first port of call.

 

Mine was doing the exact same, until i changed the lambda and it's much better now approx 5+ miles extra. But i have got a heavy foot.

 

Ace thats what i thought it "should" be just wanted a couple of opinions on it,

Next question where is the best place to get one from, IIRC its a 2 wire sensor sitting on the crossover pipe uneder the engine, there is nothing in the main downpipe