P0688 & random shut off
 

My 07 Rango 4.7 Limited FLex Fuel keeps shutting off randomly. While driving as well as idling. I have to pull over, take key completely out, than restart it. Always restarts(but i have to remove key i cant just turn it). i am to nervous to drive it. I took to the dealership. They kept for 2 weeks. Claim its the main harness to injectors/coil that is faulty. Quoted me $3,000 to repair. insane right? After bringing it back home i checked the whole harness and found that it has no splices as they claimed. As well as 80% of the harness wasn't even messed with. i think they gave me an outrageous quote knowing i would say no, so they could be done with it. I have read everything on the internet for this issue and have yet to come up with a fix. engine was rebuilt 1 yr ago, pretty much ever sensor in car is new. issue started a couple months back.

ALWAYS GET A SECOND OPINION.
Ended up costing $53 to fix. spark plugs were my issue. water was coming in from cowl by where windshield wipers are and landing on coils and plus causing them to rust and overheat therefor causing the auto shut down with code p0688.