I have a 96 A4 2.8L and yesterday my check engine light came on. When I got into work I pulled the codes using the smog station.

P0172 System too rich bank 1
P0175 System too rich bank 2
P1250 Fuel Level too low

So im really not sure why the fuel level code popped up but after i cleared them the light stayed off. After work Im driving home and everything feels fine and after the engine warms up the light come back on. Im not sure if its the same codes so im going to check tomorrow but im assuming so. After the light came back on, my acceleration went to crap and it shudders really bad now when I step on the gas. Any Ideas on where to start looking or what to do? The only thing i have done was about a month or so ago i did a sea foam treatment to clean the injectors. Followed the instructions fully and had no issues. Thanks guys

 

Check the air filter,and clean the MAF sensor first. Other causes could be a faulty O2 sensor (but i doubt it) or a faulty fuel regulator.

 

Turned out it was the MAF sensor. All it needed was a little brake cleaner on it and its as good as new.