Making vehicle stop in front of wall using stepper motor and ultrasonic (HELP)

gifted:
I'm just asking for some feedback on the code i tried but doesn't work, if you're too stuck up to help don't bother...

You have had quite a lot of feedback. You don't appear to be taking any notice of it. If you're not willing or able to take advice it's not surprising if people don't bother offering any more.

You need to be using non-blocking code. PulseIn and anything with delay in the name are not non-blocking code.

And error reports like "The motor turns on but nothing happens." really aren't helpful.

Steve