Ok, my 2000 s4 6spd stalls as soon as you let out the clutch. Before it started having this problem it was bucking at highway speed and the EPS light came on intermittently. I scanned it with a snap-on diag tool and it had fuel trim codes for both banks one and two and it said lean and rich on both banks. This made me think MAF or 02 sensors. Now i can't get a scan-tool to comunicate with the car and it won't move. It seems to run fine and boost when in neutral. Then I can put it in gear with the clutch in and its fine, once I let the clutch about half out it stalls. Any help would be appreciated.

 

So I had the car in today and scanned it again still no communication. I remember it seemed to cut out over bumps, so I started bumping the car up and down at different spots. After I started smacking the ecu box it started cutting out. I pulled it apart and found that the ecu hold down clip was missing. Now I bought the car used and I know it was in an accident, but why skimp on a couple dollar clip when you replace the whole ecu? I'm putting in a giac x chip and taking out the apr chipped ecu that is in right now. Hopefully this is the problem with the fuel cutout as well, I'll let everyone know.

 

Yeah keep us posted

 

The new ECU is in with the GIAC X Chip. Still have the same problem. I personally got into the Mitchell on Demand Flow charts (Auto Diagnostic Reference Site) and checked the EPC light is showing that it comes on with a throttle by wire code. Nothing with the ECU. So much for the ASE Mastertechs I work with. Anyhow I don't have a code in the system stored, but like i said before I don't have a VAG scanner available only global obdII scanner. I saw in another post that it is usually just a throttle body cleaning that is needed but I was wondering what the next most common problem is?

 

Cleaned the throttle body, checked all connections to the throttle body and the pedal, all look fine. Pulled and cleaned all the connections and I still don't have a solid ECP light to pull a code from. Any Ideas?

 

Basically you are running way to rich? I would check the fuel pressure regulator, if it looses it's vacuum, it will run rich. Or it might just be broken.

What do the spark plugs look like?

 

And the problems was...... a broken vacuum line from the rear of the intake manifold to the fuel pressure regulator. Was setting all kinds of codes and made me think it was an electrical problem. Ah well at least it seems to make more power with the GIAC X Chip.