Hi Phil good to see you yesterday! i would swap lambda's over and see if problem changes sides!!! sounds to me thats where the fault is .
Skullmog wins the prize - top of the class Sir!! Seems that a track-days' worth of engine vibes had shooken the connector for the RHS lambda sensor loose - it was still visually 'connected', but probaly a few mm's out. I'd already removed LHS Lambda ready for the swap, so I switched sides regardless and went for a test drive. Initially that stuttering problem was still present (now on LHS pipe), but it soon cleared and we're broadly back to where we should be. I guess that loose connection prevented the Lambda from sending reliable, workable signals and it was only as the mapping moved onto Open Loop that the car ran correctly again. Closed Loop wasn't talking too well. There must have been a lot of clag build-up in that lambda as it took a while to clear and it's still very slightly evident, although not that you'd really notice.
So I am planning on popping a couple of new lambda's in there just in case.
Thanks for all your help folks, and there's a beer waiting for you Kev when we next get to a pub somewhere :-)
