While driving the car will just die. took it to a mech he changed the cam sensor and still the same problem. he now tells me i have to take it to a ford dealer to have it checked because he thinks the problem has to do with thw oil and only ford dealers has the tool to check it

get an OFFICIAL diagnosis from someone with a much more sophisticated reader. It doesn't have to be the dealer... just a good mech that specializes in GM

P0340 is cam position sensor. P1685 is for the key(has a chip in it) P1684 is battery has been disconnected. If the engine will still crank then codes P1684 & P1685 are probably old codes. So if the car will still crank, lets forget about those codes and focus on P0340 A bad cam position sensor will cause the engine to die and not allow it to start back up. Replace the cam position sensor and clear the code and the car should start up.

replace the crank shaft position sensor the cam sensor will make hard starting not no starting in most cases

Pull that distributor cap and watch the rotor as it is cranked. If the rotor doesn't turn the timing chain is broken and causing your problem. If it doe look at the crank position and Cam Position sensors.

Have you checked the cam sensor and crank sensor?

spider injectior supply fuel to the cylinder when they go bad thats how they act hope

When was the last time you changed the fuel filter? when clogged, they will cause the engine to stall when stopped, or while driving. Inexpensive, if you can do it yourself, Part cost-under $15, for most cars. Won't do any harm to change it, know what I mean?

only half way there if you have a tbi check the crank sensor/ cam sensor that is the first line of business on that truck if the crankshaft sensor fails the truck stops dead when you wait a few minutes the sensor re energizes and the truck will work again for a bit antiknock can cause similer problems but not while the truck is running

I would seriously have a cat put back on you need that back pressure and have the O2 sensors replaced. Sounds like it may be time for a major tune up

It is most likely to be your fuel relay, however check your fuel filter and fuel pump.Hope this helps