I had this same exact issue 2 weeks after installing my Pulsar. Diablo Sport has sent me a new unit that I have yet to install.
I had a grounding issue prior to installing the first Pulsar that I actually fixed by "cleaning" the ground attachment point. The dealer said they could not find any other issues. The truck ran great for a few months until I installed the Pulsar. Now that the Pulsar has been off the truck for a few weeks I haven't had any issues. I will be giving the Pulsar another shot though, when I install the new unit next week.
So the truck threw the service electronic throttle control code yesterday afternoon. Stopped, turned the truck off, started it again, and all was fine except the check engine light stayed on.
When I got home, I disconnected the negative battery cable and disconnected the two big connectors that plug and clamp into the Pulsar. I then re-tightened the screws holding the Pulsar onto the ECU. (They were fairly loose.) Reconnected the connectors onto the Pulsar, and reconnected the battery. Started the truck, and the engine light was off. Drove to work this morning, about 22 miles, and no issues.
Fingers crossed that re-tightening the Pulsar onto the ECU and removing and re-clamping the connectors solved the problem. Maybe something was loose and was not making a good connection. Time will tell I suppose.