hey guys, i just got done fixing my engine light on my 97 audi a4 2.8 and now its back on...i checked the codes and i got p0401-generic egr flow insufficient,p1109-bank 2 sensor 2 voltage too low/air leak,p0136-generic o2 sensor circuit malfunction(bank1 sensor 2) can any please help me on what to do to fix these? thanks!

 

The codes for banks 1&2, sensor 2 could either mean that you have two bad post-cat oxygen sensors or two bad catalytic converters. First thing I would do is clear all the codes and see what comes back. What did you do to "fix" the CEL last time?

 

well i did just that. I cleared the codes and it hasnt come back yet but i havent drove it that much since i cleared them. Also i replaced my #29 fuse and it made my cel go off. then 30 mins later it came back on with different codes. the original codes that came on were tank valve ventilation electrical malfunction and all 4 o2 sensors but when i replaced the fuse nothing showed up until it came back on with those 3 codes.