[s-cars] Engine cutoff + code 2413 fixed

[Wayne Dohnal]

I was having a problem with the ECM cutting off the engine after reaching 15 
psi boost, then cutting it off at 5 psi after that until it was shut off and 
restarted.  The only trouble code was 2413: Mixture Adjustment, adaptation 
limit exceeded.  The symptoms are listed as sooty exhaust and reduced fuel 
economy, suggesting a rich mixture.  The spark plugs confirmed a rich 
mixture.  After testing every sensor, the injectors, and the spark, I got 
around to pressure testing the intake plumbing and found the problem: A torn 
turbo outlet hose (from the turbo to the crossover pipe).  The Bentley lists 
one of the possible causes as a bad signal from the MAF sensor.  This would 
be the case with the intake air leak, but it sure would have saved me a lot 
of hours if a hose leak would have been listed as one of the causes.  Just 
to be complete I'll mention that the bypass valve was also broken, causing a 
vacuum leak.  I doubt this would have contributed to this  particular 
problem, but I did fix that at the same time.

The car is a daily driver and I don't want to buy a whole set of hoses just 
for the heck of it, but after seeing the list price of this hose at $445(!) 
I took a crack at repairing it using 3 layers of black RTV gasket maker 
reinforced with fiberglass cloth.  So far, so good, and I think it has at 
least a 50% chance of being a good long term repair.  I'll also mention that 
a workaround for the engine totally cutting out is to just unplug the WGFV. 
This limits boost to 5 psi, and the ECM doesn't cut off the engine, which is 
pretty inconvenient when you're in the middle of trying to pass somebody.

Wayne
1994 S4