I'm getting a lean at idle fault code. I have 70,000 miles on it, so I decided to replace the O2 sensors and MAF. It doesn't seem to have any vacuum leaks, so I thought that should take care of it. It didn't. Although after installing the new MAF, I see that it wants to hunt a little bit at idle.

I put in a new DV a few months back, but it didn't start acting up until recently so I don't think that's the problem. I also have a K&N and a 2 1/2" exhaust, but those were installed well over a year ago.

Is there anyone out there with any ideas?

1998 1.8T Quattro

 

mass air flow, would be my guess. I think they are trouble, on the 1.8's.

 

Look harder for vacuum leaks

 

yeah the shop said that my engine air/fuel flow was fluxuating (pardon the spelling) a little at idle and that it was probably the mass air flow and if it blew it would be a ton of money, forget how much sorry, if i remember right, which is unlikly i think they said $500 just for the part. But there was a extremely lenghy precedure to rule out mass air flow. They do it just to make sure they don't install a new mass air flow unless you really need it since they are really expensive.

 

Doea it only set off a fault code @ idle?
If you have checked everything out
I.e. O2s, MAF Vacum leaks
Put a Fuel gauge pressure tester on and see wat
you getting,if it is low find a good spot to block off the
return line and the gauge should go up, or pull the fuel regulator
Pressure should go up
if not you have a bad pump or fuel regulator valve

 

Yes, I've checked absolutely everything. Thanks for the tip on the fuel pressure. I'll check that next.

FYI- I was able to get a re-manufactured MAF for $70.00 from ECS Tuning. You have to check the part number, though. They don't make re-manufactured units for all A4s.