TorontoSteve

Thanks to all for your input.

UPDATE:
I took the car to Audi Downtown Toronto (164 Avenue Road, Toronto). They looked at it on Saturday and service advisor Jason said that the throttle valve was full of carbon (soot) and that they also needed to clean the fuel injectors and then run engine diagnostics. Jason also said that the brake warning was because of a faulty ABS module (which costs $650 plus $360 labor to replace). I told him to forget the brakes (they work the old-fashioned way without the ABS system) but to do the rest. Today Jason called and said that the car was running ok, but I should also have all the front suspension arms and right-rear sway bar links replaced (there are 4 suspension arms per wheel, and one of the upper ones was replaced during the safety inspection 2 months ago). [Jason said that work would cost about $440 plus about $2000 parts.] He also said that the front brakes flex hoses were cracked and should be replaced. Given that the safety was done recently, I think he was exaggerating the severity of the wear in the arms, links & hoses, although the other advisor insisted that the safety should have revealed these worn components. [The invoice only mentions 4 of the 8 suspension arms, so that suggests that Jason was indeed probably fishing for an excessive repair.] I'm relieved that there is no need to replace the alternator or do any transmission work, so the $573 bill for what they did (includes $115 to diagnose brakes, $115 to clean soot, $115 to clean injectors, $115 to scan engine, plus solvents and tax) doesn't bother me too much, although it was, of course, over-priced.

The engine scan revealed these errors in memory:

Motronic fuel inj. system: throttle position control; power supply (B+) termminal 30 Low Voltage
Climate control: ignition time period signal off (incorrect signal, sporadic);
Central locking: key 1 adaptation limit exceeded; short circuit to B+; open via crash signal; alarm via luggage compartment switch; alarm via inetrior scanning; alarm via door contact switch drivers side; alarm via door contact switch pass. side; alarm via terminal 15

[oddly there was no ABS/brake error listed]

Maybe several of these could have resulted from the recent battery problems. The service advisor wasn't there when I went for the car so I'll ask him tomorrow about the short circuit error, etc.

About the surging throttle issue:
I guess that the guy who did the safety couldn't have know about soot in the throttle valve. I wonder if I got dirty gas on my last tank-up, which was at a small, kinda seedy garage at Courcelette and Kingston Rd (the receipt does show "Premium gas" though).

About the electrical problems:
I have been careful not to leave anything on in the car so I guess the first battery was just old. The spare I put in was not new either, so I assume that I must have left something on that drained it, unless there really is a short somewhere. The 2nd battery might even still be ok -- I will get it tested. I have the new one in now in any case.

I'm tempted to start hunting for a vag-com. Maybe I could turn off the brakes warning with that (it blinks constantly and beeps 3-times every 20 minutes or so). Any leads would be appreciated!

When I got the key back from the dealer today, the remote didn't work. I assume they dropped it but when I complained Chris Z. said it would cost $225 to replace! I think I'll pass on that too. Chris also refused to give me the first name of the guy that worked on the car. Can't say i recommend Audi Downtown Toronto....

Snow Rocket

Could it be something as simple as throttle body adaptation?

Black_RS4

you can buy a vag-com at ross tech... just search them in google. as for the rest, I'd hate to say it, buy eBay the control arms... you'd be suprised by what you find.

1move

iTrader: (1)

Ebay = wrong way to go check a few audi parts sites... cant recomend any cuz i am not at home but I will get those to you when i ge thome tonight or tommorow.

Snow Rocket

I got a complete front arm and tie rod kit off E-bay from deutcheparts. All parts were individually sealed in plasic bags stamped Hamburg-Technik. as was the box they came in. Supposedly OEM manufacturer, all parts looked identical to parts coming off except the missing Audi logo's. Are they as good? I'll let you know in 100k. Kit cost $300 shipped. So parts off E-bay are worth a shot, unless you like to spend money (maybe I like to change parts more often than neccessary).

TorontoSteve

One more follow-up:
I went back to ask the service consultant who oversaw the work to ask about the short error. He wasn't in and the other guys weren't much help with that. A different service consultant was more reasonable about the key remote no longer working and re-programmed it at no cost (normally $90!), but he made it sound like a favour ("a courtesy"). They wanted $27 for two spare batteries--I got the same ones (CR1620) at circuit city for $5 each. Do the keys really need to be reprogrammed every time the batteries die or are removed?
The car is running but there is an acrid smell when I rev above 3000RPM. Either they didn't clean the throttle right or they missed something. You'd think after $230 to diagnose the brakes and do an engine scan that they would have found out the cause of that.... Now I'm driving around with a fire extinguisher on the passenger seat....
Snow Rocket: by "throttle body adaptation", do you mean the throttle body might not be seated correctly?

1move

iTrader: (1)

Yes key's do have to be re-programmed every time I wrote a thread on how to do it yourself in the DIY section of this site