Sorry guys I posted this by mistake in the R56 column.

 

For the boost implausibility error, did you check for air leaks in the charge lines? It looks like previous owner replaced everything maybe something isn't tight. It seems like this is only happening under high load so the leak might not be noticeable when you're inspecting the car under no load.

Also look at your BOV.

Is that superchip remap removable? You could try removing that.

Check out this thread:

https://www.northamericanmotoring.co...de-2885-a.html

Has this happened since you bought the car?

 

The notchy shifting is probably due to the people using crappy trans fluid when they replaced it after the clutch job. You have to drain the transmission before you remove it for a clutch swap and who knows what they put in. Get some OEM Mini transmission fluid if you can and the shifting should improve.

Your other problem is that you're overboosting. Basically the ECU can't properly regulate the boost and it peaks at a high enough boost level that the ECU goes into limp mode so that something that doesn't break. Overboosting is fairly common on poorly tuned turbo cars. You mention an Alta exhaust. Do you have an Alta downpipe? I would get rid of the Alta boost port adapter and the blow off valve and the superchips tune and see if that fixes it. Then if you want you could slowly add them back and see what causes the issue. There isn't any permanent damage. You can drive it just fine you just can't accelerate hard in the upper gears.

 

The car has the Alta downpipe.

 

Pics

 

Forgot