I doubt he can put a lien on your truck unless he has a work order to do the exact work he did, such as replace the computer. He may have 'per telcon 4/13/18' indicating you gave permission on 4/13/18, as a notation on the work order.
Other than that, he has no grounds to do the work as it was not authorized.
I don't know what he's charging for the computer, but they should be in the $120-150 range, ballpark. Got on for an EEC-V 97 6 3.8 for ~$130 re-man from Cardone via parts house.
Fixed my problem. Not fun to install, as the box was in a uncomfortable place to work.
You do not owe him anything in that he has failed at his profession. So, no labor, but the parts he did pay for. Get him to show you the invoice, and pay what he paid. No more. No 'retail' or 'suggested list' price, as it did not fix what he said it would, and you are no better off than before. He should not make money with failed diagnosis and no repair. You will have a discussion.
Once 'freed', get the truck out of there, perhaps take the time to drive to your new location, slowly, and find someone more local.
With EEC-V, or EEC-VI, dunno, you should be able to pinpoint misfire, fuel pressure, coolant temperature, requested rpm, developed rpm, cylinder contribution, long and short-term fuel trims, and just about everything that the machine is doing.
There is a 'data gathering' mode, Mode 6, which will let you look at misfire counts accumulated, per this startup, and ongoing to actually look at what each cylinder is doing.
If you do have a true misfire in #2, get back to the basics. Fuel, air, spark and compression are needed. Which one is going away?
Start from scratch.
tom
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