DB9 Top Gear Track
AO Silver Member
Join Date: Jan 2007
Location: United Kingdom
County: East Sussex
You have to take the battery/tray out, it's bolted to the side of the airfilter box and has a hose going off to the turbo. The lower bolt is a pig to get at.
Having said that, if the 147 JTD MAF is the same as the GT JTD (and why wouldn't it be?) it's a sealed unit, the sensor cannot be removed for cleaning.
I went through all this, the symptoms you describe are identical to mine, I could drive round town all day with no hint of a problem, the MCSF error and limp mode would kick in toward the end of my 35 mile journey to work.
By all means fiddle with the MAF, however it's almost certainly the swirl valves in the inlet manifold.
All the best