surging question
 

I am having an intermittent problem with my truck surging on occasion. Seems to be no pattern or reason, it will randomly surge as if I hit the throttle and then act perfectly normal. It is showing code 1694 pcu and none in ecu.

A few weeks ago it had the dead pedal and bad surging and was throwing 0122, 0500, and 1694. I replaced the APPS and the truck ran smoother than ever and all was well until this. I don't remember the details but a couple years ago we did the noise suppressor/grounding thing that fixed the converter locking issues.

The truck has 280,000 on it and other than the occasional surge runs absolutely perfect. Any ideas where to start would be appreciated.