So I am fairly new to the forums this is my first post and I have come across I problem that I can not figure out. I have an 03 Ram 4.7 v8 everything under the hood is stock with around 160k miles.

Seeing as how the stock plugs were still in the truck I decided to change them out. I replaced the stock champion that were in the truck with NGK V-Power plugs (which I have researched and people love them in there dodge truckss). EVerything went well but now I am getting obd Code P0358. The only thing apparent that I can tell is when I rev up to around 4000 rpm I cant rev any higher and sounds like a cyl is missing and I would assume its cyl 8.

Code P0358 is Ignition Coil 8 Control Circuit. Since I just changed plugs I pulled the coil off checked the wires on the connector and all seemed great. To test the coil I put the cyl 8 coil on cyl 1 and vice versa. Still getting error codes p0356

Just in case it helps I also have error codes p0456, p0441 and p0113. I know 456 and 441 are to due with evap system and I am trying to locate the link and 113 is to do with the sensor in the air box (which I started un plugged to throw the code)

Any ideas or suggestions on what to try now I am fully stumped as what the problem can be at this point? My next step is to pull the new plug and put the old one back and see what happens.

 

If its not the coil pack then it's probably a faulty plug or it's incorrectly gapped. Try a new one. If the stock plug has 160k on it, it's worth a few bucks to just buy another one. You can try swapping the c8 with a different one and see if it throws a misfire code on the new cylinder and that should let you know for sure if the plug is bad.

 

Ya i did not think it was a faulty coil as if changing the faulty cylinder coil to another one and the same code remains tells me its not the coil.

I did put the original plugs back in and runs fine but in park if i rev it up to 4k its like it has a limiter still and sounds like it is missing. Though I did a test drive and petal to the metal was getting up to about 6k before it would shift no signs of missing or limited rev. I am completely stumped. All plugs were checked and gaped to .040

 

The rev limiter is what won't let it go past 4K.

"Code P0358 is Ignition Coil 8 Control Circuit. Since I just changed plugs I pulled the coil off checked the wires on the connector and all seemed great. To test the coil I put the cyl 8 coil on cyl 1 and vice versa. Still getting error codes p0356."

The fact that the code changed would indicate the problem is not the plugs. Are you sure you didn't switch the connectors for six and eight? They're right next to each other. Since the problem moved, I suspect you had a poor connection to the coil on #8. When you swapped the coils, you "fixed" that, but jostled the connector for #6, maybe. A shot of contact cleaner on the coil connections may help along with a dab of dielectric grease.

Yes, the P0113 will probably go away.

 

Ok I was unaware there was a rev limiter on the truck never noticed it before. And I was a typo did have a P0358 not p0356.

 

In that case, check the gap on #8. I bet it's too close or too wide. Too wide would seem unlikely.