BSCA4

2 Codes: 0171 & 0172 Lean & Rich. Why both of them? What should I look for? Idle a bit shaky, Could not locate any vacuum leak, new MAF.

lyleswk

Do you have a CEL? Are these "intermittent" on the VAGCOM readout?

If you have a CEL or they aren't intermittent, it could be lots of stuff. Link to diagnosing both codes.

http://wiki.ross-tech.com/wiki/index...01276#mw-pages

BSCA4

I just read these codes on a ODB generic reader (my VAGCOM won't read after I install NAV+). Yes, there is CEL intermitent, engine shaking when start up. Just replace brand new MAF.

lyleswk

So the CEL tells me that these aren't "intermittent". Bummer you can't get VAGCOM codes as they would aim you closer to the problem. Only suggestion is to look at the 2 diagnostic lists in the Ross Tech link and see what is common. One that does jump out is fuel delivery. Pressure? Bad injector? Etc?

BSCA4

That what I suspect also (car had 150K on the clock). I recall I did fuel filter when I bought the car (120k)