Well, it got really bad. The Seafoam is a temporary fix at best, but it does help. I have narrowed the problem down to the fuel system. The injectors are good-I swapped from one bank to the other, same issue- so I think it is either the computer or the O2 sensors. My theory is that the O2 reads too rich and shuts off fuel to that bank of the motor. This is just an educated guess since the Seafoam would clean the exhaust and the misfire goes away for a few weeks. Well any help is greatly appreciated, thanks Chris J.

 

I first day back to school and CEL came back on when I backed off of gas at bottom of large hill on highway. p0300 general misfire runs great 1 1/2 hour drive to school and I cleared codes and no CEL on drive home.
I think computer thinks that when I slow down under 70 it must be misfiring.
When I plug the Snapon scanner in and read the TPS it always shows 13% when throttle is closed and 70% at WOT. I have had 3 different TPSs on it and they all read the same.
could this be a short in the harness or normal.

 

I don't know enough about the computers on these to answer your ? or mine... I guess I will break down and let the dealership run a full diagnostic on the truck. I wish they could tell me if it will isolate the problem before I fork out $90 to run the tests. I'll be sure to ask about a short in the harness when I get some extra money to get the test done. BTW Fdup, have you ever replaced the O2 sensors on your truck? Service tech told me today(9/8/09) that it could be the O2 or the central computer in the truck. Either way it'll be over $200 to fix it.

 

My Dodge Dakota was running great. No major problems since I owned it until just recently. I had it a little over three years. Had plenty of power. Used plenty of gas. So I put a hho kit on it about 4-5 months ago. It ran even better. About 3 months after I had that kit installed it nearly kicked the bucket. Now remember it was running way better, NOT worse.

I was on my way home from work one day (about a 6 mile drive) and just as I was turning onto my road, something stalled the engine. When I tried starting it, it started on what sounded like 4 cylinders (was actually running on 6). I had to really give it the gas to get it the rest of the way home. The truck immediatelty threw a check engine light. After studying it out and running my scantool on it, I discovered 3 codes. P0201, P0202 and P0208. I took it to my local machanic 9/14/09.

He went discovered it's not the injectors like it appeared to be. So today and tomorrow we'll hopefully pin it down. Dodge machnic first blamed it on the hho kit, thought it had fried the injectors. Now he thinks it's something internal, inside the engine. Just glad I got that aftermarket bumper to bumper warranty after all

I'll keep you posted.

 

I did it said the broken spring. I caused the P0201, P0202, and P0208 codes! Yipee! I made him look like a dummie. It wasn't the wiring harness to the injectors, or injectors. It wasn't the GCES kit either.

Dodge machanic said it was due to a spring in cylinder 1. Messed up a few other things in the process. Therefore no compression in several cylinders. I didn't get the details except now they need to rebuild all but the whole left side of the engine.


Thanks to y'all for your Dakota postings.

 

How long after the new tranny did the problem start?
I have heard that a slipping tranny can cause misfire codes.

 

It actually was before I replaced the tranny...I think...I thought the trans was the problem for the truck stalling, and it was part of the problem. The TC was full of metal, as was the valve assembly. I didn't find out of the misfire codes until after AAMCO reset the error codes, that's when the p301,303,305 codes popped up. I am still thinking it may be the O2 sensor or the cat clogged up, but a spring could do it too. Dodge tech here in Winter Haven told me that.

 

Well, I think it is finally fixed. Plenum gasket was bad. a real pain to change out but it runs fine now. I wasn't using oil, so I didn't consider the plenum. I talked to Tim @ Hughes engines, and he diagnosed the problem right over the phone. Save yourself some time and call these guys first. Mileage is a little better, but I still need new O2 sensors. Found them for $35 on ebay! Good luck to you all.

 

I've still got my misfire, the light goes out every couple of weeks but comes back on a couple of hours later. My mileage has always been real good around 22mpg but I only drive highway and keep up with traffic, I put just over 700 miles a week on and check mileage every tank.
What all did you need for gaskets? while I'm doing mine I might keep going and take heads off and do a valve job, It's got 150,000 on it.
Let me know if the CEL stays off on yours this time.

 

It's been a few days, and no problems other than other electrical stuff on the fritz. And it did stall once about 15 minutes after I first started it. I ordered the plenum upgrade from Hughes Engines, It's a 1/4" thick piece of aluminum instead of thin steel. I did have a leak, but I never lost any oil. The whole inside of the intake was covered in oil. As far as gaskets, you'll need the intake manifold set, it comes with everything. Don't forget the "black" silicone gasket maker for the ends of the intake gaskets. And you need an inch pound torque wrench and lots of time! When I ordered my parts from hughes they sent all new bolts also (a 1/4"nc-20 and a 5/16nc-18 tap will make things easier). You will need lock-tite for the plenum bolts and I used straight edge razors and 220 grit sandpaper with a sanding block to clean the surfaces. And a lot of brake cleaner. If you rebuild the whole top end I think you will need new head bolts. If mine starts acting up again I will just replace the springs and guides from the top without removing the heads. Good luck, if I can help anymore let me know.