ECU vacuum hose

[Barbera <barbera@twd.net>]

I am having problems with my '89 200q.  The car keeps fouling spark 
plugs, and when it runs, it hesitates under load.  I checked the 
computer fault codes, and it reads 2221, suggesting there is a vacuum 
leak going to the ECU.  Is that the pink plastic hose that goes from a 
check valve at the engine to underneath the back seat?  If it is, I 
checked it, and everything seems to be alright.  I was able to blow 
through the hose with no problem.  Is it possible the mechanism that 
reads the vacuum pressure is faulty?  Maybe one of the check valves is 
bad?  Any suggestions would be greatly appreciated.  Thanks.

Tom B.
'89 200tq
'86 4kq