96 Plymouth Voyager P0300 P0306

My wife has a 96 Plymouth Voyager with the following two codes. P0300 and P0306 I know that one of them is a misfire in cylinder 6 and the other is a random misfire. Has any one else had this problem before. And if you did how did you get it fixed. I was told by my mechanic that I had to replace all my fuel injectors at $125.00 each. If you had it fixed cheaper or know of the correct eway to fix it please help me out. Thank You

what size engine? I doubt very much that you require a fuel injectors(s)! any performed a compression test yet?

Hi, I'm in the middle of the same problem with code P0306 in a 2000 Plymouth grand voyager. The only symptom is rough idle, at stoplights etc. Otherwise is strong and runs fine. Over the last two months I've literally put well over two thousand dollars into trying to eliminate it at no avail. The reason i'm persistant is that it is otherwise awesome iwth brand new transmission. 1,450 went into replacing supposedly burned valves (which was the surefire reason) and two cam shafts along with related engine parts. 500 went into having two separate shops change out the electrical because both insisted the problem lay with the plugs, wires or coil. No help whatsover. Oh, and 270 to get all six injectors cleaned at a local machine shop. Didn't help at all. Now a Plymouth shop is telling me it's gotta be either a burned valve (even though I told him I've had a valve job done) or a broken piston ring (even though compression is perfect). I'm at a loss, I personally suspect a sensor like a MAP sensor or oxygen sensor or idle sensor, but none of the real mechanics agree with me. Personally I'm done with the professionals for now. I've gotta go with my own research like this forum for a while.

Start with the basics ¡ and cheaper ¡

Change sparks, clean the injectors, check the spark wires, if they are old change them with good brand new ones.

Keep posted

I'd still be leaning to a valve issue unless the egr sensor is junk or the flexplate is cracked and shiftted. That happens alot after tranny re and re

I was having rough idle at stops. Found a forum couple years back indicating the 3.0 engine has a possible clearance issue with the idle air control valve. The claim is that dirt/gum build up can keep the IAC valve from moving freely. My fix has been to spray some intake cleaner into the throat every time I change oil (about 6 months). Seems to keep the engine idling smooth.

But, my 96 Gr Voyager 3.0 with 206k miles also gets P0306 codes more recently. I have tried wires, plugs, cap, rotor and code came right back. Used some STP complete gas treatment and code went away for 2 months. My freeze frame data from 2 days ago is Load=3.9%, Coolant=206.6F, Short term fuel trim=-0.78% lean, long term=+5.47% rich, intake MAP=5.7PsiA, 608RPM, speed=0MPH.
I can see a periodic missing flash when the timing light is on wire #6, before and after changing wire/plugs/cap/rotor.

Since gas treatment fixed it for 2 months, I am thinking of doing it again. Any suggestions on a better cleaner of the injectors?

everything in your limitted freeze frame data looks normal, The freeze frame should help you replicate the conditions that it occured under but Im not a beliver in pour in fuel system treatments. If the cel falshes then it's a pretty substantial misfire so start with the basics like verifying compression and cylinder leakage, switch the injector from cyl #6 to another cylinder to rule it out but at that vintage of 3.0 ltr and van I'd be leaning towards a likley valve problem.

I don't seem to have the continuous smoking issue of the older 3.0 valve seals, but...a couple times last year, I was pumping out lots of smoke when idling around a parking lot in Colorado (7000 feet above sea level). But haven't noticed that since. I also got a weak catalytic conv code when at high elevation, but that has not come back since returning to the east coast.
I do use a quart every 800-1000 miles, but I'm pretty sure all of it is leaking out the valve covers while running (never get more than a couple drips on the driveway.) I can smell the burning oil dripping across the exhaust at times when stopped.

I guess my question is, what happens to the valves? Is it just a simple issue of wear for any engine. And, at this point, is it really worth doing anything about it? The engine seems to run fine. I think I can continue to get thru yearly emission inspections by clearing codes about 1 week before inspection. (giving time for self tests to complete.)

I am on the original catalytic, fuel pump/filter, injectors, hoses. Have had timing belts, water pump, transmission, muffler replaced. Only hose issue was needing to cut an inch off of the fuel line where it jumps from the strut tower to the engine. Started to leak at the hose clamp.

I have always been skeptical of gas additives. But it seemed to work that time.

The 3.0 ltrs had several issues with poor valve guides leading to the oil burning you're experiencing. If you already have leaking valve cover gaskets then my suggestion would be to remove the heads and timing belt, have the heads reconditioned, the water pump, timing belt, cam and crank seals replaced and you should get anohter 200 000 miles out of that engine. The 3.0ltrs were a very durable engine with an incredibl strong bottom end. I for one don't condone clearing the cel before inspections to get the vehicle through. At then end of the day it's a polluting vehicle and should be repairred or retired.