Any Issues Remampping High Mileage Diesel?

Chipped mine at 110k, no problem. Maker sure everything is working before you start , strongly recommend you use someone with a dyno and do a before and after run. Things to check: the MAF, the EGR is cleaned out, temp sensors are fine, N75 is working properly, new air filter, the air intake pipework for leaks, the BRAKES!! Get a VAGCOM test and clear any faults you find. Should anything go wonky after the tune up then you can be reasonably sure the remap has done something, and will stand a much better chance of getting the tuner on your side to sort it. Select your tuner carefully, if the price seems to good to be true then it probably is