hi there, i've recently had a problem with my van, its developed a loud diesel knock, theres no warning lights on the dash, i've had it on the computer and the diesel levels on pot 3 are very high, i've pulled the injector and fitted a new one along with copper seat, i've tried to code the injector to ECU, but it wont let me, the snap on diagnostic computer says 'can not perform task' after going through all the options and entering the code.. so i tried it on another computer, this time a hella GUN TEK, this lets me do the same, enter the code and then flashes up 'can not perform due to ECU fault', so i've had the ECU tested at ATP in cannock, and they say there is nothing wrong with the ECU, can any one shed some light on this???
TIA colin

Have you tried leave engine ticking over until engine temp hot 90 c try recode then ? Or will old injector recode back on? Is there a relearn ecu option on your diag machines?