Typing this from my phone, please excuse errors. Did a timing belt/water pump/thermostat change this weekend. Before this, car ran like a champ. Now I have issues. Here's the story.... after completing the installations, I flushed the radiator several times and finally filled with dex cool/distilled water at a 50/50 ratio. The car was difficult to start, but finally kicked over after several seconds. It idled roughly and was puffing white smoke/steam from the tailpipe. It got a little on the hot side with the coolant gauge reading about 3/4. The heater was not blowing hot air. I double checked that the thermostat was correctly installed, but I did some internet cruising and came upon bleeding the coolant system. I had not yet done this. I simply filled the radiator and reservoir and fired it up. Upon accessing the bleeder hose and elevating the reservoir, I got the system to take much more coolant. I filled until coolant ran out of the hose. I started the car, much easier to start this time. It still had a very slight stumble occasionally, but much improved. The white smoke from the tailpipe stopped. The heater was blowing hot again, and the car was no longer overheating. I pulled the breather hose off with the car running to try and burp out any remaining air by squeezing the upper radiator hose. I should note the upper radiator hose was hot, the lower was not. The car seemed to be running right by now, so I take it for a spin. NO low end power. I would equate it to feeling like the car was in 3rd gear, trying to climb a hill from a standstill. Once past 3k rpm, the car runs strong. Anything less and it is a pooch! Any ideas?
Here are my thoughts... the symptoms may match with fuel filter, clogged cats, bad turbo, coils, head gasket, etc... but the coincidence of those falling while the car sat doesn't make sense. Remember, it ran great before I got my hands on it. Could it be that I could a plug while it was airlocked? Is it still likely to have some airlock, and if so would that cause my problems? Could it be a computer issue due to sensors thrown into whack?
One final note... I had the battery unplugged during my work, which usually clears my CEL for awhile. It came in almost instantly when I started the car the first time (don't know what code, don't have vagcom). Also, after the final test drive, I shut the car down and let it cool for a half hour. Returned to start it and the idle was again rough and the coolant temperature was still at the half mark.
Sorry for the book, thanks for helping!

 

Could a plug = fouled a spark plug

 

Bump... Help!

 

My intial reaction was the timing is off and the car is in limp home mode. I have not changed an Audi timing belt and do not know if it is possible to install it out of time.