P0116 - Engine coolant temp Ckt range/perf
P0401 - EGR flow insufficient
p1104 - Manufactuer control fuel air metering?

So, I'm kind of lost on where to start, given that this is my first problem with my first Audi which is a 1996 2.8 quattro btw. With the egr not getting enough flow, so i can imagine that its clogged or has some kind of build-up on it. as for the others.... I need some help. one more bit of information that might be useful, is that the first code was p0401 then a few weeks later came p1104 then recently i started getting p0116. HELP!

Thanks,

Matt