need help with my 99' Chrysler 300M plz!!
 

Am having problm with code P0354 (coil #4) Replaced sparkplug , and coil pack and I checked if wire was open it was i fixed it wid new connector .
Code still shows up and misfire still present.
I switched coil pack problm was still there at coil #4 .
Then i have code P1391
Car still starts
I changed camsensor (mopar)
Ntn have changed
Havnt replace the cranksensor becoz i cant find it
I search all over on forums etc for help mostly find can b my PCM causing that so i buy a remanufactured PCM and the trouble codes are still there
And my battery light wont come off
Buy new alternator and new battery .
I've notice a weird thng , when the battery light is off car runs smooth , no rough idle ,no misfire and when its on complety opposite .
is that normal ?
I dont know what to do anymore , can u plz help me out if possible.
Thnks and advance .

A crank or cam sensor is and will not be used for one cyl issue
They check the cam and crank location for all of the cyls

When it is missing get a test light and unplug that coil then see if u are missing 12v or the ground pulse it will blink real fast.

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You need to fix the battery light first. All modern cars depend on a proper operating charging system so the computers (PCM) can function properly.
You state it runns good when the light is off.
Battery test and confirm OK (most auto parts will do for free)
Connections clean and tight. Disassemble the jump post and strut tower ground, clean with a wire brush.
Charge wire has a green fusable link in it at tha jump post. Make sure it is good.
SSR fuse in the under hood fuse box. Controls the voltage regulator in the PCM.

I checked it Ground pulse not really blinkin, and it have 12V .

Just the other day i was tellin myself if i shouldnt replace all power wire and ground , cause some the ground wire/strap look like they need changing

Stay on point with this not a battery issue nore an alternator issue a batter light issue and a single cyl misfire happening at the same time will not be a battery nor a ground strap. Why i say its because a battery is the whole cars power buffer or source same for a ground strap its not for a single system. Get a wire diagram and trace the coil ground to the pcm and make sure the alt ground supply and the coil ground supply are not part broken if the wires are good not grounded to power or ground then u are looking at a PCM issue then.

Ok, i will check that when i reach home from work but u thnk da could of damage the PCM (2days old)

U made no mention about replacing a pcm.

Well sorry yes i did , ok i bak traced the wire dat goes frm the alt to pcm and its fine frm wat i saw on the diagram

And the ground to coil is fine also !