05 Dakota 4.7 P0300 Misfire

[mdetwiler]

I'm a newbie to this so excuse me if I don't have the proper etiquette. I have a 05 Dakota with the 4.7 116k miles. I have read many posts and watched videos but have not seen any with this specific issue. The truck runs fine from initial cold startup and warming up. Once the truck is at operating temperature and turn off for a while (maybe 15 - 20 minutes) and restarted is when the problem occurs. Idle gets rough, the engine tries to stall and recovers but I will get a flashing check engine light for 10 - 15 seconds and goes out or a solid check engine light. The only code it ever throws is the P0300. I have looked at the live data which seems OK based on what I find on the Internet. I replaced the plugs (OEM Champion from NGK a year ago or so), the throttle position sensor and air flow sensor. Cleaned the idle air control valve and throttle body. Not getting any specific cylinder misfiles so I am assuming (I know) the coil packs are OK. Initially, I got a Bank 2/1 O2 Sensor code, replaced it and immediately got a Bank 2/2 O2 sensor code and replaced it. Thought the catalytic converter initially but the more I read online moved past that??? I found a list of possible sensors to replace but hate to start down that road. Next on the list were the crank and cam position sensors. Thought I would give the forum a chance first. Let me know if you have any questions. Thanks

 

[OC455]

There's a whole list of things that could cause that from what I could see. Low fuel pressure, vacuum leaks, loose wires, broken piston ring, broken valve spring, bad head gasket, burned valve, timing chain skipped aside from what you already listed and checked.

Maybe start to eliminate the easy stuff first. Compression check, any loose wiring, dry rotted vacuum lines...

Short of taking it to a shop an let them go through a diagnosis.

 

[mdetwiler]

So, I think I have it fixed. It has been two weeks of driving with no issues. Pulled the wheel well cover on the passenger side to check the wiring to the crank and cam shaft sensors. I found that 3 of the bolts on exhaust manifold were broken and the back half of the gasket was completely gone. Replaced the bolts, gasket and heat shield and all seems to be good. Hope this helps someone. Thanks