I have one in the shop that is causing more grey hairs than I deserve. It came in with the mil on, code 91, 110. We did a scan on the accelerator sensor and it was glitchy so we replaced it. better but not there yet. the 110 is from engine overheating, the radiator is clogging. The symptom is low power, no miss or stumble but no power. Full throttle from standing start until you eventually get to road speed. The trans shifts are almost stacked and do not change with accelerator position. The modis shows 100% throttle and load properly and the boost comes up to 18 lbs. seemingly in a timely fashion. The original symptom was driving at highway speed the engine would lose power and slow way down, pull over and let is sit for a while and it would go again and this was intermittent, maybe once a week. This is a box/delivery truck and has had very little maintenance. We did a transfer pump test and it failed so we replaced filters (air & fuel) & transfer pump. a friend at the dealer told me he had one like this and cummins told him to replace all 6 injectors but he didn't have the weird trans shifting problem either. Any Ideas? Transman It has the allison automatic trans.