So i sold my MS PnP and went back to my stock ecu,as well as the bocsh tps sensor and replaced it with the original. Now when i come to a stop the idle will sometimes drop to close to 600 maybe 500 rpms then back up to 1100 a few times then settle at 900 where i have it set. Its wierd it doesnt do it all the time, ive been searching for the problem for a few days now. Any ideas?

 

Did you plug or remove the old PnP signal line? Maybe a vacuum leak?

 

Sounds like a vacuum leak.

 

TEN+GND and set base idle