'98 A6 Avant: Malfunction light, no auto-shifting

[Bart Oleksy]

Our 1998 A6 Avant Quattro has started showing the malfunction light when 
driving now.

Owner's manual suggests it's likely an emissions system problem, which 
didn't *sound* so serious... but it did seem that the car wouldn't shift 
out of first gear (automatic transmission).

Also, one mechanic suggested checking the gas cap before going too crazy 
- I removed it (seemed to be on OK), put it back on (while the car was 
running), didn't notice any change and made it home safely.

Later started it up again and NO malfunction light, and it was fine for 
a while.

Yesterday, the malfunction light stayed on after starting it up again, 
and again it seemed to have trouble shifting out of first.

I understand the diagnostic code(s) will need to be checked, so I'll be 
on that as early as I can this week (want to go on a trip next week!), 
but just wondered if there were any suggestions on things to watch out 
for or to ask the mechanic about, that sort of thing.

Thanks for any and all suggestions!

Bart
'98 A6QW
'91 200TQ
'86 CGT