[s-cars] 15-00 - Adaptation Limit (Add) Not Reached

[Kevin Day]

Got a CEL today. Car is running well, with no drivability issues. Boosts
to 24 PSI regularly. The code is

00561 - Mixture Adaptation
        15-00 - Adaptation Limit (Add) Not Reached

Any thoughts? Vaccuum leak? MAF? O2?

There are (Add) and (Mul) codes listed in the Bentley. Is one the O2
trim and one the MAF base? Does "not reached" (cf "exceeded") mean the
lean or rich end of the range?

My fuel economy has been on the low side lately, but not terrible (17-18
MPG instead of 18-19). I was blaming it on the new E10 fuel. Ignition
system seems fine. Fuel pump is only a few weeks old. I think I may have
seen this CEL with the old pump but never hooked up the VAG-COM to read
it.


-Kevin
'94 S4 (hypochondriac?)