bought this truck recently from nevada, drove back to california, on the way home starts throwing p1316. of course, just my luck. unfortunately, this is a catalyst model truck so i need to smog it before i can get plates. as long as i dont have any codes i should be fine.

so 1316 comes on and off constantly now while driving. it is usually off at idle, but not always. then, as i accelerate from 1k-3k rpms the SES light will go on and off repeatedly. truck runs PERFECTLY. no smoke, no missing, idles smooth (for a 7.3 anyways), plenty of power.

i did the $.50 mod, didnt make any difference. passenger side UVC harness was pretty loose, replaced it and valve cover gasket. no difference.

my buddy did a buzz test and they all buzzed fine. did another test (not sure what) and said his fancy little scanner thing said there were problems with 4 of my injectors. looking back i think he did a cylinder contribution test. (im new to 7.3s but not new to mechanical work or diesels). he says i need a new IDM. he says that the IDM can start to get flakey and, when it does, the trucks main computer takes over firing the injectors, which is why he says my truck still runs fine. that sounded a little funny to me, but im going to buy the IDM anyways. i dont have any friends local with 7.3s that i could swap IDM's with, unfortunately and i hate just throwing money and parts at the truck. he said if its not the IDM its probably injectors, which doesnt seem right since the truck runs fine.