I did my timing chain about a month and a half ago in my 2004 dodge Dakota 3.7. Since that it had a funky idle, not quite a misfire but not as smooth as I think it would be. About a week ago my truck threw a p0300 changed the spark plugs and cleared the code. Code came back a week later adding p0304, after it did that you could feel the miss more. Took it to my work and the master tech read the live data on it and the miss only happened every like 100 revolutions on the engine, he said it was a bad lifter( engine has 260 k and I’m running 10w40 oil as I was having oil pressure issues, the truck does and always has had lifter tick) I don’t quite trust him as he’s an *** but he’s smart so maybe he’s right. Today my codes came back and I pulled a p0302 and p0304. What the hell is going on. Did I screw up the timing chain? Or is something else going on. I’ve had the truck for 2 months at this point and I’m not a professional mechanic + that was my first timing chain. Any advice appreciated

 

Its possible you could have it a tooth off on the cam gear on that bank 2. If your off a tooth it will usually still start and run but misfire and have next to no power. A bad lifter usually just causes noise and or poor valve timing on startup. So probably is bad but not relevant to the issues at hand. I wonder if you could pull the valve covers and see if the dots? Might be the easiest way to confirm without tearing out the front bay again.

 

it’s got power, I really don’t think it’s a tooth off as this problem would have shown itself in the beginning right? I could take my valve cover back off but I’m not sure what I’m looking for. The valve train is very very noisy on start up but it goes down in noise after a bit. It’s definitely still there all the time. The valve covers leak because my bum self didn’t put a new gasket on it and it lies led into the cyl 4 spark hole. But there wasn’t any on the top of the old plug. It didn’t throw any miss codes until after I did the plugs. It threw the p0300 before I did the plugs tho but not the 304 and 302

 

The 3.7 uses Coil On Plug right? Check your plugs for cracks or damage as well as burn marks on the coils. Check the gapping as well. Most of the time they are fine out of the box but you never know if one took a blow at some point. Do you have a scan tool? Check what the O2 sensors are reporting. If there is an O2 on both banks try unplugging the front ones. If the engine starts running better then replace them. Or at least the one on the misfiring bank. You can usually just tighten the bolts on the valve cover a bit to stop a leak. The p0300 is usually thrown first as its just looking for a certain total count of misfires. Its probable that the p0302 and p0304 were on there way to being set.

 

One bank? I would suspect a cam sensor.