tozoM8

It could be a sticky valve for the torque converter in the tranny.

skiracer

<img src="http://pictureposter.audiworld.com/24433/maf_vs_rpm_graph.jpg">

You can see the scatter in the data at idle (from 4 to up to 10 g/sec!) as well as some other bad data (see the flat line between 1200 and 2200 RPM). You definitely have issues with your intake system, either leakage or a bad MAF.

Always Overcharged

how did you do that -very clever

KMU

small hose. The secondary pump shouldn't be an issue on a 97 because I don't think it has one. The MAF sensors have caused more than a few failures on this model. Don't know if the idle air conrol/dirty throttle plate would contribute to the O2 sensor codes, but several had idle/stall issues there. Not likely, but possible skewed signals from O2 sensors due to age/fuel(sulfur content) contamination issues over time--Last resort idea.

ttuling

You graphed "mass air flow (specified)" not "mass air flow (actual)" which is the next field in the display group. (See page 24-126 on the Bentley CD.) I don't know what the (specified) number means. But the (actual) numbers are much closer to what's normal at high rpm and load, and seem at first glance to track rpm and throttle angle decently the rest of the time too.

I'd still look for vacuum leaks first. But maybe I'm prejudiced against the MAF sensor being bad in this case because when mine was it caused (Mult) not (Add) too lean codes.

Tom

skiracer

Looking at the actual mass flow data along with the RPM and throttle body angle data it appears to be fairly normal. There are a few anomolies, but nothing bad. I would still suspect a vacuum leak in the induction system somewhere.

<img src="http://pictureposter.audiworld.com/24433/audi_graph_rpm_vs_mass_flow.jpg">

The data looks good, as does the throttle body data. Look for an air leak.

ttuling

Cool graph. Yeah, seems like a vacuum leak