I have a 2005 Jeep Liberty it won't stay cranked unless I put my foot on the gas and then it was shut off as soon as I take my foot off I took it to the mechanic they said that the motor is gone
Take it do a different mechanic and get a second estimate. If the motor was gone it would be the other way around. If you would have pressed the accelerator it would be shutting off if the vehicles motor was no good. Seems to me like it can be an idle problem.
Sounds like you may have a clogged catalytic converter.
Search Jeep Liberty Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Jeep Liberty Experts