Newbie with a problem

[1966ponyguy]

First of all, I’m new to the forum but have owned several Dodges. My latest purchase is driving me crazy. I bought a 2004 1500 with the Hemi. When I bought it the original owner told me he had never even changed plugs. I have driven it for about 2 months now, and my daily is about 25 each way, mostly interstate. The truck has right at 150,000 miles on it and is completely original. So I noticed the front was a little loose. I replaced most of the front end (2 wheel drive) including lower ball joints, shocks, rotors, pads, sway bar links, and inner and outer tie rod ends. I also replaced the plugs, almost half of the plug tip was burnt off after 150000 miles but the truck ran perfect. I also replaced the egr valve to clear the only code showing. Since the tune up, the truck will die sometimes when I take my foot off of the gas. Not often but it is starting to get worse. I can shift up out of gear and it starts back perfect. It also runs pretty good on the interstate. Most of the time it idles dead on 600 rpm. I have also noticed that the mileage has dropped from about 15 mph to around 12.5 mph. It is still throwing the egr code even after the replacement and now it’s throwing a new code. The codes are: P0404 and P0157. Has anyone ever had or heard of anything like this. If this was an older car, I would think it is acting like a fuel problem.

 

[tidefan1967]

What kind of plugs did you use? From my experience the older Hemi's really like the factory Champion copper cores the best.

 

[1966ponyguy]

Yes, direct replacement Champion

 

[tidefan1967]

On the EGR did you clean out the return tube to the intake? It could be clogged up with carbon. I would also take the throttlebody off and clean it if you haven't done that already.

 

[xtremewlr]

The first code, P0404, is related to the EGR system. You replaced the EGR valve but you should also replace the PCV valve in the intake manifold and make sure the EGR tube is clean. The tube runs from the valve to the back of the manifold, right next to the PCV valve so both should be easy to locate.

The second code is related to one of the O2 sensors, bank 2, sensor 2. Sensor 2 will be the rear one but I'm not sure which side is bank 2. I think passenger but I'm not positive. Start with unplugging it from the harness and then remove it to inspect. I'm not sure if you can clean them without damaging them so you might just replace it once you determine which one is the correct one. See this article on that code.

https://www.yourmechanic.com/articl...-low-voltage-bank-2-sensor-2-by-jamahl-walker

Lastly, while you are doing all this, remove the positive battery cable and ground that cable to the negative terminal. Leave it off like that while you are working on the other things or for at least 5 minutes. Once you are done with everything, then reconnect the positive terminal, turn the key to ON but don't start the engine. Wait for the gauges to stop dancing and the chimes to stop and then start the truck and clear the codes and see if they come back. Hopefully that resolves the stalling issues too. Mine did the stalling thing the first time I changed plugs. Resetting the PCM by disconnecting the battery as I described helped because the PCM is then forced to relearn everything and will pick up the changes that you made. That goes for doing mods as well.

 

[1966ponyguy]

Thanks, I shorted the positive to the negative but only for about 30 seconds. I unhooked it again and will leave it that way until the morning. I’ll keep everyone posted

 

[xtremewlr]

Thanks, I shorted the positive to the negative but only for about 30 seconds. I unhooked it again and will leave it that way until the morning. I’ll keep everyone posted

Some people will say that 30 seconds is enough. I'd rather be sure and do it longer. Just IMO.

 

[1966ponyguy]

I can report back that after leaving my positive terminal on my negative over night the issue is better. The codes have not came back yet and a quick check of the mileage using the over the windshield shows a little better at 13.6.

It still wanted to die several times, with the rpms dropping almost to 0 before it came back up and stayed at about 600. I’m pretty sure that it runs better cold that once it warms up if that helps anyone.

Many many thanks for the advice so far. Please keep it coming as I still don’t think it’s completely back to the way it was before the plug change.

 

[xtremewlr]

Mine did the same thing for a while and then stopped doing it. Give it some time for the PCM to learn the new tune.