Originally posted by Tom Allen
A couple of points to add, Mark, Jimmy sounds fairly clued up realising that the lpr pressure is high, and doing this to try and improve the lcd's output. Could well be the snap ring, but a well worn exhaust valve would be more likely, and as he's had the lpr piston out to do the shims, it's just a small step to change the exhaust valve too.
Oh yes, 82psi is a touch high for the current A4's, more like 65psi.