Rough idle and check engine light after new clutch?

[somejohn]

I'm really hoping someone has an answer for this - I don't think my wallet can take another failure in my car this month!

I have a 2003 Mini Cooper S, around 69,000 miles. Two days ago i had a new clutch and flywheel installed which, compared to the old one, is light and day, what a difference!

I noticed when I got the car back that the battery had been disconnected - the clock was reset - but didn't think much of it.

Since picking it up I noticed almost immediately that the car wax idling much higher than usual - around 1,200rpm at standstill rather than the usual 700. I thought it was just settling in and it seemed to correct itself over the course of the journey.

Today I took I back out and noticed that the rev needle didn't settle on idle - it ran up to 2,500 or so at ignition, settled to 700, then constantly surged between around 600 and 1,200 at idle. It still drove fine but was much rougher and louder when idling and seemed to get quite close to choking itself on a couple of occasions where the revs dropped and then sort of caught itself as it started to splutter. It's a manual if that makes any difference?

The yellow engine light has come on in just the past couple of miles (after about 10 miles of city driving since picking it up) and doesn't go away after leaving the car off for a while.

I'm going to take it back to the mechanic who did the work tomorrow but they're a clutch specialist rather than a Mini/BMW mechanic so i'm a little concerned that they might not know what to do.

I wondered if this was the symptom of a loose sensor (they also swapped the wheels front-for-back for me), or if the ECU was still trying to reset itself after the battery was disconnected but if anybody has any idea what might be causing it, I'd really appreciate your help - at least I can take it back tomorrow with some possible suggestions then!

Anyone?

[somejohn]

Hi Guys,

I know nobody's replied but I just thought I'd update on the off-chance that somebody reads this and is able to help. I got the car hooked up and the fault code read, it came back with P1242 - 'Manifold oressure sensor before compressor'. Apparently there's a sensor under the bonnet that's stopped firing but the mechanic also suspects that it could - potentially - be the throttle body.

Has anyone come across this fault code? How did you fix it?

The more I read up on it (and there's very little information I can find about it online), the more likely it seems to be a short in the wiring somewhere throwing the fault, which would make sense given that it's just had the flywheel and clutch replaced.

Anybody?

[MINIAC]

Might be the bypass valve ...

p1242 site:northamericanmotoring.com