Ok sorry if it's out there, but I tried to find something in this and just kept up with I have a bad misfire I'm getting misfire codes exc. I am overhauling my 1996 Ford f150 4.9l and one of the things I did was replace the harmonic balancer. It has a trigger ring attached to the old one that I can't find anywhere and can't get off of the old balancer. The new doorman one didn't come with it. Is this something I will need to run the truck properly or is it just something that will shoot a code. Any help would be much appreciated.

 

A very vague explanation. I would reinstall the original balancer. Then I would diagnose your misfiring condition.

 

I don't have a misfiring issue i thought my question was pretty clear do I need to reinstall the trigger ring in order for the engine to run properly or is it a sensor that will just shoot of a code.

 

The MD is not used for engine management - it's strictly an emissions sensor. The codes it sets when it detects misfires MIGHT alter engine management strategy, but certainly NOT the code for it being open-circuit, or for NOT detecting its tone ring.

(click this text)

 

Thanks a lot I kinda figured it wouldn't but figured it doesn't hurt to ask here and see if that was the case because the auto parts store call it a crank shaft position sensor. Or I think they even called it a cam position sensor and I was like it isn't on the cam for sure.

 

That "part" is actually in the distributor. Ask me how I know.
changing my distributor didn't help my 0171 0174 codes either.
My next step is diagnosing/replacing fuel injectors.

 

No, the MD is not in the distributor. And fuel injectors never need replacement. There is no failure of an injector that can produce either of those codes.

 

I haven't read the entire thread. (Searching for another issue.) However I had a similar problem. LSS. It ended up being the MAF. First time I've ever had one go bad and throw a vehicle into a limp mode state.

{Also check the fuel relays. Passenger side kick panel.}

 

See if your harmonic damper looks like E bay item number 233787239934
If yours has a sensor and a trigger wheel, you need it IMO
A normal truck would have or better yet, you should have a TFI distributor and a E core coil with a fender mounted module IMO,and no trigger wheel on the damper, but they do exist