“Please” does anyone one have any solution to code P0304

[KGWilder]

“Please” does anyone one have any solution to code P0304
I have been working on my Aunts 2003 PT Cruizer 2.4L turbo it has a code PO304 cylinder #4 misfire she had a shop do a tune-up left the shop could not hardly make it her home like running on 2 cylinders took it back and they said she needed a new motor #4 compression was 40, then she heard that I use to work for Carl Berger Dodge out of LaMesa, CA she contacted me to fix it I scanned it code P0304 and P0340 came up I checked the compression it was 110-115lbs, found the rubber insert of a sparkplug socket still on the #4 plug the plugs not gapped right about .30 and worst quality plugs and wires , they just fell off the coil she went and bought quality parts (plugs and wire-set) the car ran great for a couple days then the MIL came on with the code P0304 only, cleared it with scanner, but keeps coming on changed the coil-pack still comes on, changed the cam positioning sensor, still on, “Please” does anyone one have any solutions to this problem cause I am out of ideas, also when you turn the key to “on” the MIL blinks 10 times, then next time 8 times, she got Bosch +2 plugs I checked for part number it said none available I told her to get NGK’s but came back with the Bosch’s also checked spark with spark tester and cyl. #1,#2,#3 spark is consistent but #4 is not consistent even though 1 and 4 spark together, any help would be greatly appreciated. Thanks!

[Taggert_LOA]

platinum plugs in a turbo are a no no. the engine is too hot for the plugs. it destroys them. what you need are a set of ngk 4306's gapped to .35.

[Taggert_LOA]

there also a tsb for an ecm update for the 03 which deals with the cam sensor issue. might want to see if the ecm was updated with the new software. also the crank position sensor can also throw a p0340 code. that is located in the front of the engine located right above the starter. and only use mopar sensors. any others just don't cut it.

[KGWilder]

Thank you,
I told her to get NGK's but I should of went myself I also changed the CPS but still did not fix, I will try the plugs first cause it did run perfect for a couple of days the plugs probably got hot and are damaged now. thank you for your feedback!

[quicksilverdon]

Easy on a turbo - swap the plug & wire for # 4 with another cylinder and see if problem moves...
Does it idle smooth? If not, spray WD-40 along intake manifold seams by # 4 - if idle smooths out, it's a bad intake gasket.
Did you use a dealer cam sensor? There are bad aftermarket sensors out there.