Hi, thanks for the reply. I have had it checked by EDM who couldnt find anything physicaly wrong but said it could be something with the ecu, so i had it checked and there was no errors in the ecu. They suggested the only thing it could be is the relay. On the fuel pump issue, it started to squel after a long run (2 hours), i only heard it when i got stuck in traffic, but now it can be heard after just a few minutes running and it really seems to be straining. When i called Jeep to get a quote for the pump they said they have had quite a few go lately. Seems strange and my jeep has under 30k on the clock. When i frist purchased the jeep i had a fuel tank leak and on investigating it appeared that the tank had been off and the seal hadnt been put back in right and had fell into the tank itself. When i contacted the dealer they admitted that the car had been on display ramps for 10 months and when they started it to move it they had ran out of fuel but dont know why they would have taken the tank off and that was over 15 months ago and so dont know if my current problem was the cause of something they did back then.
As for the tyre sensors they can be a pain but i have found them to be a great aid whilst towing incase of slow punctures etc, although the idea of having an all metal sensor exposed to the elements seems a really bad design.