2003 1500 van 5.2L 3 spd

the van has been missing, nothing major , but enough to throw codes. Today I had the plugs , wires, distributor cap and rotor , ignition switch , air filter , belt and tensioner replaced. Cleared the codes , paid for the work and the check engine light was on again before I was out of the lot.

I turned around and they hooked it back up to the computer and it was showing misfires on different cylinders than before. This happens everytime , the codes are for different cylinders each time the light comes on. so then they sprayed brake cleaner around the intake manifold and the upstream O2 sensor showed some drastic jumps on the computer chart. But with the intake being right above / beside the manifold the shop owner wrote off the option of it being the / a issue .....

I just got this van, just put another $500 into it today and still I'm dealing with a very very slight random misfire..... I need some expertise !! Please help

not that I'm aware of ... along with the hard start it seems to be eating fuel and has loss of power in the accelerator... any ideas ? Thanks !

I changed the crank sensor. No changes in symptoms. I was wondering if you had any ideas past that.

she has loss of power in accelerator , bad mpg , cranks for about 5 seconds before turning over when cold , but fires right up when it hasn't been off for long.