The 7.3 looses power and then may regain minutes later or not at all. Check engine light comes on when power is lost, and goes off when power is back. Have checked and changed fuel filter in bowl, drained water. Was told it was a faulty TPS, changed the pot switch. This seemed to help for a short time. Had the codes read while it was running decent, PO236, PO122, PO123, PO603, and PO221 were shown. Was told the accelerator assembly needed changed because the one switch was not working. This was when it was running good. I have found that when the pedal is pushed down the actuator on the on/off switch had not been made buy the arm on the assembly. I put a shim in between the switch and the arm and restarted it and it ran great. I thought I found the problem and this woul be a simple fix. I tried to start it the next day with the shim in place and I got the same old problem of which seems like half the power. I try to rev it up but can only get about 2000 on the tach when it does this. While I was thinking and searching for something else to check it ran ruff and then great 4 times in about a half an hour. Where can I get a code reader since I don't want to chance taking it on the road until I find the problem. Any help would be greatly appreciated. Thank you!