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Q: Keep getting misfire codes p0300,p0301,p0303,p0305.Misfires all on bank one. on 1998 Dodge Ram 1500

P0300=means multiple misfires detected.
P0301=means cylinder 1 had a misfire
P0303=means cylinder 3 had a misfire
P0305=means cylinder 5 had a misfire.

Truck will lose power, burn gas, may idle bad at times. Codes will sometimes pop up when under light load. Lately added some stp treatment and codes will pop up after driving for about 15 minutes.
Also noticed that the transmission/engine will rev up high at around 55mph when trying to accelerate. I have already done a lot of troubleshooting and parts replacement.

Replaced the following.

2.Spark plugs twice with auto lite and champion copper.
3.Spark plug wires three times with autozone duralast wires.
4.IAC valve
5.MAP sensor
6.Purge solenoid -twice
7.Crank position sensor
8. All related fuses to fuel and ignition.
9. adjusted throttle position cable going to [COLOR=blue !important][COLOR=blue !important]transmission[/COLOR][/COLOR]
10. Several tank fulls of lucas.
11. very religious with all fluid changes
12. PCV valve.
13. Air filter twice.
14. distributor and button duralast from autozone.
15. replaced alternator due to a dieing alternator.
16. followed tsb 18-48-98 that pertains to plug wire rerouting several times..
17. Replaced both upstream and downstream 02 sensors.
18. I have read several post and videos and they all seem to take me around in circles.
19.Ohmed out the injectors on the lean bank and they are all about 14.6 to 14.8 ohms
20. I have done seafoam through the brake booster and there were no white smoke atleast not a lot.
21. Replaced with a new cat last fall and had it re-check last month.
22. recently remove the muffler it was falling apart.
23. air temperature sensor
24. coolant temperature sensor
25. coil pack.
26. fuel pressure ok 52 psi.

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Strange that all the cylinders are on the same bank. Dont leave much but injector pulse, vacuum leak at intake.
Fuel INJECTION on that bank may still be you problem. Oscilloscope and a real scanner will tell you what the problem is. Or someone with that equipment can.
I think you have been driving my truck. Haven't seen a post since February. Did you find your problem? If not I would have to say check the harness going to the injectors on that side, spray carb cleaner around the intake on that side. You certainly sound like you know what your doing but I thought I did too, found last week that my new cap I put on a while back was not tight. The screw on the passenger side, the pain to reach one, had bottomed out on me without touching the cap. The old cap had been on so long it corroded and pulled some threads out. Ran a 5mm tap thru distributor to fix that problem. Long story short it had been that way for months. Check engine light came on couple weeks ago I think it was p0302 and p0306 or 8, the 2 nearest that screw. Fixed cap got rid of codes. The distributor itself could also have some play in it causing a multiple cylinder misfire.
I seem to have the same problem with a 2010 Dodge Grand caravan. I go up and down a steep hill everyday. I have the codes P0300, P0301, P0303 which I checked at autozone. I replaced sparkplugs and wires, coil, MAP sensor, EGR Valve. It lacks power going up hills with RPMS shooting up when given acceleration. It crawls at 30 miles, I also notice when in drive and I hit the shifter over to the left im seeing im in low gear 2nd or 3rd. Its an automatic. My question is to you keybrowns, hopefully your still around.. After all you went thru, how did you come to that final determination with it being the transmission pressure solenoid, did you have it analyzed to get that answer and if so what should I have done to have that test... Thankyou... Good13Guy
I'm still getting an intermittent misfire on #6 , but your description reminds me when I started trouble shooting this cylinder 6 problem I did the whole 9 yards... plugs, wires coil, rotor and distributor cap.
After doing all that shortly after I was getting misfire codes in other cylinders at random, and it was horrible... .
When I went back to check the rotor I happened to look inside the cap and noticed that the connecting center nipple that goes to the coil was missing!
Huh??!! WTF!? Turns out the rotor I bought had a slightly shorter contact blade on top, and what happened was the blade somehow got caught under that damn nipple and sheared it right iff... there was still a come tion, but the little ball bearing like piece was floating around inside the distributor plate jumping around like a Mexican jumping bean in there causing all sorts of fun connection misfired and refires, etc...
Moral of story... spend extra for a good rotor and heavy duty cap. I went cheap and paid the price...
Still can't figure my number 6 misfire..already replaced the bad lifter and will run fine, and then throw a code at me after a few days... clear it, a few more days and 6 is at it again...aarttggghh!
I had the same codes finally replaced the Crankcase positioning timer and all codes cleared and haven't had any misfires since
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