1998 Dodge 1500 throwing P0300 code

Im new to AF but i have a problem with my dodge... I have random/multiple cylinder misfire.... I have changed plugs,wires,cap,and rotor...... I have also check my compression an i have approximatly 145-155 psi through all 8 cylinders.... where do i go next??? i have had alot of problems with this truck.... such as flywheel teeth, 4 Crk postioning sensors, fuel pump, an so on...... im about to pull out my damn hair!!!

My thoughts would be to check out your injectors. There was a similar problem a little bit ago and here is the thread. He had some major shaking and found out it was major misfires and he replaced his injectors and the problem was solved. So I would suggest having them looked at before anything else.
http://www.automotiveforums.com/vbulletin/showthread.php?t=387461

Well im not saying your wrong about the injectors but i checked them 1 by 1.. unpluging them an listening for a difference or not.... well that brought no luck..... ever 1 i unplugged seemed to have an effect on the idle..... But i did look down in the intake an found a oil looking substance on the plenium... could this be my problem??? because that would cause a vaccum leak right? if anyone knows please say..... im lost on this truck...... But ill keep you posted on my results for everything i try....

The plenum gasket is known to be a problem on these trucks. if you have oil in there it needs to be replaced.
Matt

Well i just finished up my intake gaskets an plenium gasket today an it didnt help..... i started it an its really quite.... it sounds like an air leak but it would have to be exhaust because my pipes hardly have any flow now..... i just put manifold back duals with 40 series flowmasters an it was loud until this crap.... could it be another crank sensor??? hopefully someone will know.. well i will report all progress if any.... an keep you all updated on the wrong things ive tried....

not sure if you already mentioned it, but did you check your plugs?

P0300 is a misfire code. You have to do all the normal checks that can cause misfires. The comp. is able to code injector problem so don't think that will be problem. Vacuum leaks, plugs,plug wires, pcv. Have you found the cylinder that has the misfire? Dirty injectors could cause this. Do you have scan tool? If so look at fuel trim. This will give you idea about the injectors and which bank to look at.

I know its getting plenty of fuel cause it smells of straight gas at the tail pipes... or i think it is... im taking it to a local dealer here an haveing them run the codes an see if they can figure it out im am clueless on it an im getting too much money into unneeded repairs..... i have got about 1800$ in parts in it in the past month.... im gonna let the dealer deal with the crap... ill let you all know what they come up with.... hopefully they will figure it out...

the brand new cat pluged up due too the plentium gasket.... i had it running again an now it died an wont start.... an no matter how long you hold the key it wont build oil pressure??? any got a clue i dont!

I think I would take the oil sending unit out and install gauge fpr testing. Manual gauge to make sure it has no oil pressure. It could be a bad sending unit.

i got oil pressure... i found some broken wires an some clips that broke on some plugs so the plugs came unhooked... i fixed the wires that broke an zip tied the plugs together an it runs great..... i was thinkin that it was strange how it happened an shit.... cause it went from fine to dead in an instant... i guess the movement of the engine when i reved it up made the wires that were messed up loose there connection so im in business now... i would like to thank everyone that has gave me ideas to go off of... so thanks to all of you

The same basic thing is happening on my 1999 Ram 1500 4x2. 81000 miles. I have been getting the P0300 code for a month now. The truck is harder to start. It is ruff idle and misses terribly between 1 and 2nd gear. Seems to smoothout at higher rpms. I have changed the Cap, Rotor, Wires, Plugs. I changed the injectors in cylinders 3 and 8. I have run BG44k injector cleaner through system 2 times now. Where are the wires you found broken located? Is this what actually fixed your problem?