93 S4- intermittent 2224 error code

[Steve Mills <smills@lineage.com>]

As the subject indicates, I've been chasing an intermittent 2224 error for
a couple of months now. Symptoms are as indicated in the Bentley- slight
misfire/surging at WOT. Possible causes listed are:

1) Intake air leak after turbo- Seems unlikely- hoses have been pulled,
checked & reseated.
2) Wastegate bypass regulator valve malfunction- Checked, tests OK.
3) Vacuum line between intake manifold and ECM has leak- I've checked this,
but I can't find any obvious leaks.
4) Pressure sensor in ECM is malfunctioning- Since the problem is
intermittent, this also seems unlikely.

	Any ideas what else to look at, or the best method for testing the various
 intake/ECM hoses for leaks?
	
	TIA-

	Steve
	93 S4 (runs great _most_ of the time)