does anyone know the common problems for a 2001 audi s4 ??

 

HAHAHAHA.....sorry. *Ahem*

I own an '01 S4 (stage 3)...basically, the check engine light is just your car telling you it's still alive ;P.

Alright...on a serious note, the audiworld forums will be a great help to you. Become a member (free). This site is great for local stuff but for the B5 S4 it's lacking in tech knowledge.

I've passed 300k on my S4, so off the top of my head, the problems I've had (and those that are common) are in no particular order:

EGR Sensors go: they cause bucking when getting off the gas usually
O2 Sensors go: trigger CEL and affect fuel mileage
Rear bearings go every 100k give or take: whirring noise when turning (gets quiet turning in opposite direction)
The after run coolant pump sometimes takes a leak a little early (intake manifold must be removed to replace)
The passenger side valve cover seals and or cam tensioner seals will leak eventually causing a nasty burnt oil smell in your car (your cabin fan is just behind that manifold)
Dead pixels in the dash are common

Other "problems" I've had which I'd consider regular maintenance considering the mileage interval:

ICM's will go around 200k (causes misfires...nasty ones)
Turbo's will go around 170k (earlier if you chip)
Front end (all suspension arms) will be due around 160k give or take ($600 ish to replace)
Shocks will most likely be due around the same time.
Timing belt every 100k ($350)

Apart from that...the S4 takes a beating and keeps on going. Personally, I think with the age of most B5's out there: unless you have a substantial amount of cash aside for car maintenance (the brake job is over $600 in parts), you'd be better off finding a newer less complicated car. Unless of course, you're mechanically inclined and do most if not all of your own maintenance.

The B5 S4 is a great car but by no means is it cheap to maintain.

Great quote I once read: "Cheap, Fast or Reliable: you only get to pick two"