Problems with 1.8 when warm.
For the last week or so my 156 1.8 has been running like crap when it warms up. The idle drops and splutters around 500rpm and takes a heavy foot to get it shifting, when accelerating its fine but when maintaining speed it comes on and off power like the throttle has an on / off switch. Now before it happened i ran the car for a couple of days with no air filter, and had the down pipe changed.
I thought maybe maf sensor but when they have failed in the past they have been dodgy weather its warm or not. my other thought was the o2 sensor was damaged when changing the down pipe which was done 2 days before it started but i had it plugged in at my local garage this morning and it didnt throw any error codes up.
My mate said maybe crap in the fuel filter? any ideas?