Hi there mate,
You can also try the below procedure, it may reset it .
I have also added a link to an earlier thread about this issue so maybe have a look through that, it's at the bottom of my reply .
I found this link about s54 throttle adaptation reset
http://www.evo.co.uk/buying/buyingguide ... oints.html
IT READS
Curiously, the throttle system can go out of tune. Resetting it can improve throttle response and its really simple to do:
Turn the ignition on and wait for 10 seconds, then turn it off for 10 seconds, then turn it on again for 10, then start the engine.
Maybe its worth trying, not sure if it will work but its worth a go
previous thread...
viewtopic.php?f=2&t=57362&p=841138#p841138
Good luck