I've had a fairly productive session this morning. My old fan belt was showing its canvas, and the spring loaded jockey wheel wasn't looking too clever, so as my (expensive OEM) replacements had arrived I swapped them over. I'd also bought some new fan spanners, so the viscous fan unit came off very easily. The jockey wheel was a bit more of a challenge until I realised the spring unit was held on with a splined head bolt rather than a hex. With the fan out of the way I renewed my assault on the hex socket screws holding the EGR pipes on. I had tried them the other day and the ones on the manifold had of course rounded out as soon as any force was applied. I tried various things, including attempting to get an Irwin bolt grip socket on their heads and getting a stud extractor on, but in the end I sacrificed a hex key the next size up, ground it down a fraction so it would just hammer in (the James Martin manoeuvre) and managed to shift them. Hooray. Much better than spending hours with my girlfriend's dremel trying to grind them out. Everything's nice and loose ready for me to buy an EGR bypass kit. New jockey wheel on, new belt on, start her up to see if it's running true. Covers on, out for a little run to check it's all OK. Surely it shouldn't be this easy? Must order an EGR bypass kit now.