My rebuilt 2004 mustang gt doesnt seem to give me power, and when checked from the mechanice says misfiring of injector 5 then injectors fine. So I wanted to get my computer reprogramed and was wondering where and around how much would it cost? thanks

 

if you get a SCT tuner most places will charge by the hour, about $90+/- an hour for a dyno tune.
Make sure this is your problem first.

 

1. What was rebuilt?
2. Unless the stock tune has been messed with, this has nothing to do with the computer unless it is somehow defective.
3. Don't do anything tuning wise until you have fixed the loss of power problem first. You will only complicate things and make troubleshooting even more difficult to do.

Are you posting any codes?
MIL light on?

Start with the basics and move on from there.
Once you get the engine running smoothly, then start tuning.

Just my 2 cents!

 

Make sure the #5 injector wires are securely connected.If that doesn't fix the problem swap the #5 injector to another cylinder.If the problem follows it's a bad injector.If it stays with #5 it's in the wiring.
I'm not very knowledgable about just how the ECM controls the engine but I wouldn't think the computer would pick out a single cylinder to screw up.????