I had to move the wires around on the fuel pressure sensor which is a texas instruments (TI) sensor, i managed to find a wiring diagram online so saw i needed to swap the wires around as i had them wrong.
The connector is one that you cant pull the terminals
back through the connector and it needs to be installed with the wires through the connector and crimped there.
I had to get them off but i didn't want to trim any of the wire off as it was the right length so i trimmed off half of the terminal and pulled them through
I used a crimping tool but it shows why it is always important to test your crimps,
You can see it had not crimped the back correctly on the insulation and also that the bare wire was not sufficiently crimped so it failed.
Using another crimping tool i was able to crimp the insulation and wire separate and ensure it was crimped well.