Shift delay is to heat the cat rapidly for emmissions and aide in attaining closed loop. .. that is why the code comes up on Emmissions DM led [ 26] instead of the other modules .
The problems is if the delay is not working, you will always bring up the code .
Many guys BB the line and live with code erase when it comes up.. This can take seveal weeks .
Cat heating can be accomplished by holding/delaying the shift manually w/gear shift lever when car is cold .
I do it by habit, just cuz i know the advantages of getting the car up to temp and into closed loop as soon a s possible and want a clean cat......................
The advantage to the BB's is if there is a vac leak in the delay actuator/element [ most likely], then the BB'ed line prevents the engine from having to deal with the leak.................