Hello,

We have an '03 Durango 4.7L that we bought used back in March. Long story short, shortly after we got, it threw the P0456 code. Then it also threw the P0302 code.

Ever since we've had it, if you started it up immediately after putting the key in the ignition, it would take a few seconds to start. But, if you waited until the whine of the fuel pump stopped, it would pretty much start immediately.

Over time, though, the idle at startup became more rough. And if you gave it gas after startup, it would act like it would want to stall, it would come close to stalling, but it never did. Then, a couple weeks ago, I noticed it felt a little rough while driving...couldn't quite put my finger on it, though. Sometimes it felt like it would hesitate or not "catch" immediately....I guess that's the best way to describe it. Never stalled though.

Well, I found out code P0302 was something to do with spark plug #2. So, this weekend, I had my husband replace all 8 spark plugs, and he replaced #2's ignition coil for good measure.

Well, the idle still felt a little rough. Driving seemed ok though. Then, remembering that maybe the code needed to be cleared, we disconnected the battery & the turned the key to start for 15 seconds, then reconnected the battery.

Well, since reconnecting the battery, the idle at start up has been VERY, VERY rough. RPM's low, acts like it wants to stall, but doesn't....RPM's go up & down slightly. When down, interior lights dim slightly. When giving it gas, it stalls. Doesn't stall on its own, just when you give it gas. Driving, though, seems ok. Codes haven't come back yet...but it's been driven about 20 miles or so since resetting it.

So, what else could be the problem? Is there something else my husband should do/check? Anything we forgot to do? Also, could code 0456 have anything to do with it? I know what code 0456 is, just don't know what's throwing it. I know it's NOT the gas cap, LOL!

Now, keep in mind, anything we know about vehicles, we find out through the internet or through that Haynes manual. My husband is not very familiar/comfortable with these newer vehicles, but if easy enough & explained well, he will attempt fixing it. So, if you could explain things in layman's terms, that would be great! We hope to be able to fix this ourselves, since we can't afford the high labor charges at a shop. Thanks in advance for your help!

 

Updates & more detail:

'03 Durango 4.7L 2WD AutomaticTransmission

RPM's are low at start up - rough idle/low RPM...but it cycles up & down...it's like the engine is trying to correct the idle...but not really succeeding. While it's doing this, theinterior lights dim slightly & then go back to normal. When giving it gas, it stalls. Doesn't stall on its own, just when you give it gas.Driving, though, seems ok.....BUT, there was one time yesterday I was in a parking lot, in Drive, but at a stop, waiting to turn down a lane, and it stalled. When I pulled into a space & put it in Park, the rough/low idle returned. Codes haven't come back yet...but it's only been driven about 25 miles or so since resetting it.

 

I'm no expert with the 4.7, but it sure sounds a lot like a battery problem. Clean the battery connections really good and see if that helps, otherwise it might be time to replace your battery.

 

OK, thanks. I'll be sure to have my husband check the connections & go get the battery tested.

 

Check where the battery cables connect inside the PDC (relay box) too.

 

+1 on what that_guy said, another thing you could try tho is take out the Idle Air Controller (IAC) from the throttle body, clean it with intake cleaner, and then clean the passage on the throttle body where the IAC sits. That is the only thing that I can think of that might cause this problem, and not throw a code.

Also, P 0456 is telling you there is a small leak detected in the fuel evap system (and will keep coming back until the leak is fixed, however sometimes takes a while to come back), slide underneath the truck, and in front of the gas tank, behind the cross member (big metal bar going from the driver side to passenger side frame rails), there is a little black box with rubber hoses attached, go through and follow all the hoses (even the ones in the engine bay), inspecting for cracks. If you find a crack, replace that hose with fuel grade hose. The cracks usually develop at the connecting points. That should fix that issue

 

Thanks for the ideas, Rock.

I will let my husband know about them.

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Update: Tuesday evening, my husband checked the battery/connections. The positive one was a little loose & corroded. He cleaned it & tightened it, and it seems to be running better. Idle is not perfect, but it hasn't felt like it wanted to stall.

Then, this morning (Thursday morning), the engine light came on again, and and I thought it would be 0456 since we haven't addressed that one yet, but when I checked, it was code 0302 again! Any idea why it would give off that code again, even though all 8 spark plugs were replaced, as well as #2's ignition coil?

 

could be a bad/weak fuel injector

 

What kind of spark plugs did you put into it?

 

Champion Copper