Ive got a few questions for the group.

First off i was wondering how many on here have a auto scan tool?

Second which scan tool do you have and how would you rate it?

I am looking to see what scan tools are available that would perform some of the test that are written in the shop manual for my 2006 Dodge Dakota Laramie.

The reason is i am getting fault P0300 which is multiple cylinder misfires and it is very random. I have been trying to keep notes about when it happens and under what conditions. IE is it raining, it is going up hill, is it under accel, things like that. When this error pops up the CEL begins flashing and the truck feels like it is running on 4 cyl instead of 8. And like i said it is very random. Take for instance this week sunday during the driving of that day did not happen at all, monday did not happen at all, tues on way to work did not happen, on way home it happened 3 times.

I have changed the air filter, oil and oil filter, added fuel injector cleaner to gas, changed plugs and other parts controlling plugs and so far it keeps happening but again it is very random.

But from my log of the times when it occurs it seems to be during acceleration just not every time and just not every day

And it is the only code, there is no changes in like P301 to P308 so that seems to indicate that it is not just one particular cylinder.

But my test tool is a generic walmart special and does not have the ability to perform the test described in the shop manual so figured i would ask around and see what everyone else does.

Thank you

 

If you're losing a whole bank, that's either the wiring harness or the hp fuel pump. Not the individual components. I'd say check the condition of the harness and see if you can test the hp pump.

 

You stated:
I have changed the air filter, oil and oil filter, added fuel injector cleaner to gas,

These will not due anything for misfire issues, just waste money.

Quit shot gunning parts and get it diagnosed properly.
Most auto parts places will pull the codes for FREE.
There should be historic codes that will point to which cylinder is causing the problem.

I would almost bet on it being a fuel pump or fuel pressure regulator issue.

 

I did get the codes read, the only code that was in the system was P0300 which is multiple misfires. Tried to see if there was anything from P0301 to P0308 which should be counters for if a particular cylinder is misfiring but none of those seemed to be active. This is one of the reasons i asked what auto scan tools others have here on this site. THis way i might be able to find one that can operate these onboard tests that are referenced in the service manual.

When i had autozone do the scan test and it showed P0300 they said it was most likely a dirty fuel injector which is why they recommended that i put that additive in the tank.

As for the plugs and such I bought the truck used of course, and i dont know much of the history of it, so one of the things i like to do is go over the truck and change fluids and plugs and such, i am glad i did because there was no way the old plugs were .040 they might have been .125 or better but definately not .040

I have contacted the local dodge dealer who says we are currently booking out late july early aug because we are short staffed. This is also why i do try some of my own things because sometimes that is one of the best teachers.

So right now their is only 2 codes in the computer, the one is P0300 the other is P0038 which is O2 Sensor resistance high, shouldnt be because they are all brand new, when i got the truck there was no exhaust on it someone had robbed the cats and such, or at least that is what i was told.

 

Sounds more and more like fuel pressure issue.

 

Yeah prior to it dying over the weekend i did notice something, and i am thinking it has to do with fuel pressure. I just dont know what and how things are inside the fuel tank. I can see in the manuals that the pump is in the fuel tank or at least that is where it appears to be but in the one picture it looks like the pump is near the top and there is siphon pipe going down to the bottom of tank. Not sure if that is correct or not but here is something i noticed.

When the tank is full, and down to about 2/3 of a tank the truck seems to run perfectly well, starting at about 2/3 tank and going down, the further down the more often the misfire seems to occur. Might just be my perception as well i dont know but it seems to make some sense.

 

I think you are on to something,
if that suction tube is sucking a little air around it,