Ok I just recently started having engine problems 1997 ford f-150 4.6L.My motor has 449800 Km on it which sees like alot recently my truck started running rough and used my OBD-II reader and it spit out a code P-0304 so I took it to a shop and they said 2 sensors should be replaced (CAM & CRANK) sensors were done fairly cheap ($38 ) for both labour was $163+ taxes I also changed the 2 coil packs (new) & wires & plugs since then the truck has not run when I went to the shop I seen the mechanic spraying throttle body cleaner down the air intake tube while another mechanic was inside turning the motor over the truck was running when it got there now It will not start they say it may be the FUEL PUMP so I have no idea but thought I might get some free advice here as I have already had to pay for 2 engine diagnostics at $105 each if anyone could give me some advice it would be greatly appreciated

 

Sounds like the mechanics screwed something up. Take it somewhere else and let them look at it. If it can be proven that yes, those guys screwed it up, have it fixed, then get your money for labor refunded.

 

P304 was just cylinder 4 missfire.
The crank and cam sensors involves all the cylinders not just one.
At this point it may well now be either the crank or cam sensor from poor workmanship.
The next shop has to start all over again.
All you do is tell them both those sensors were replaced and let them do their thing as long as they know how to work on these systems.
Good luck.

 

will spraying the trottle body cleaner in the air intake screw up the MAF sensor

 

I don't think it would, but it won't do much to help ether.
The air meter has a fine wire 'heater' that is part of a bridge circuit.
The more air that passes the cooler it gets and changes it's reistance as the signal to the computer for how much airflow there is.