After coming to a stop, my idle falls to around 400 and almost dies. It only happens after decelerating. And, if I tap on the gas peddle, the idle goes up to around 900-1000 I don't see that these engines have a conventional idle control valve. I believe the throttle body to be clean. What else can cause low idle.

1997 1.8T, Auto trans.

 

vac leak, fuel pump, fuel filter, 02 sensor, ects, maf, the list could go on.

 

double check all of your connections, possibly your icm, a friend of mine had that problem too.

 

get your ecu scanned for any stored fault codes.