I hate the feeling of being baffled with science and thankfully , the E34 M5 is not that scientific a car !
Agree to an extent Davros, but that's quite important as when I tell people we're opening a garage I always get "but what about all the car computer stuff? you need a 10K laptop!" etc.
The reality is that it's all bollocks - it's a bloody car, with a bloody engine, that takes in fuel and spits out crap - the sensors just get in the way!
I'm a computer expert (a proper, honours degree, 25 year experience expert!) - it's about the only bloody thing I'm confident with ... I know how the bits flip and I know how the programs work .... how hard can it be? Really?!
My old boy (god rest his soul of last month....) couldn't get his head around my Honda's engine no matter how much I told him it's just like his old engines (he was a Torpedo engineer - compressed diesel engines at some scary BAR figure, effectively turbo-charged underwater engines running off compressed air) - but he just couldn't understand that the computer just replaced the carb .... giving a bit more precision to help emmissions etc...
So don't all you lot think cars after our beloved M5s are any more complex -they're not .... in many ways, they're much simpler!! Look at the M5 - lots of custom bits over and above a stock BMW .... your modern M5 is a bloody 520 with a bigger engine FFS ... it's that simple to fix ... and don't let anyone fool you that you need the stealer software to do so ... you don't .... just a bit of expertise and a bit of knowledge!
PS: If anyone takes an E60 M5 to our garage then I'll send you right up to the stealer and their fancy diag equipment