| Hi guys,
Thanks for all the comments & help - much appreciated tbh the car hasn't been the same since it went into the dealers for it's last oil change.
I have very limited access to a PC as I'm not at home but once I do I will scan my dyno read outs and let you know what the engineer has said.
Hopefully it is the by-pass valve and nothing more sinister!
Vroooom Vroooom  | 
