How are you measuring boost? Should be 8 to 9 psi so may not be accurate.

I don’t know what faults are common with these Leons. I have had a 5 door FR TDI
2.0 (184) from new for 2 years with no mechanical problems.

However, be warned that if you have a dealer sticker in rear window, don’t remove it as it can damage the aerial filament. I took my sticker off and the radio went off when I put on rear window heater.

Had to have new window and had a real battle to get dealer to accept responsibility as the hand book says “do not put stickers on rear window”.

I had to pay out, but got refund after I complained to head office and put details on their facebook page.