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Vehicle Maintenance Help

Hey guys, for some reason you all have fixed my truck for me like 4/5 times when I’ve asked, so I’ll shoot again.

Symptoms:
Rough Idle
Stalling when idle
SHIT gas mileage, <10mpg
Jumpy acceleration
Very occasional rich fuel smell
All these symptoms are inconsistent, but getting worse

09 Dodge Dakota 4.7L V8
130,000 miles

My thought is the EGR valve, all symptoms point to it from what I’ve researched, and it looks to be the cheapest option to start with anyways.

I’ve changed 2 02 sensors already, and installed a short ram intake which both seemed to put a bandaid on it, but it’s getting worse.

Thoughts?

Any diagnostic codes? When’s the last time it’s had plugs and wires? (I can’t remember if that engine is coil on plug or has wires)

When you’re accelerating and acting “jumpy” does the check engine light ever flash briefly?

Are these symptoms constant, or do they come and go?

Squats and milk

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Please don’t squat your truck OP :joy:

I live in NC, Carolina Squat baby (holy fuck I’m kidding)

It threw a cat code and an 02 code a while back, both went away after I changed my 02 sensors.

Check engine light is off

The symptoms are consistent(ish)
They stick around for a month or two, definitely stronger during seasonal changes, seem to get better when the weather has been consistent for a while. I dont know if this sounds crazy, but it’s what I’ve noticed

Couldn’t tell you about the plugs, I’m mechanically autistic. I’ll look when I get out of work

Those dodge things use champion plugs that IMO are junk and struggle to go past 60k miles. Your symptoms could very well be a misfire issue from way over due plug changes. Could also be the egr.

Both are cheap, I’ll tackle them this weekend then, thanks for the insight!

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Where is the rich fuel smell coming from? Under the hood?

Crank position sensor? Rough idle and stalling on idle could be crank position sensor.

When the engine stalls, does it restart straight away?

If that was the case it would throw a CEL, assuming he is correct and there is no light/codes, I’d say this is on down the list of parts darts. Unless he has access to some diagnostic software lol

I am with wanna_be on it likely being due to ignition. I would first check to see if the boots are on the plugs snuggly. One being loose will cause all of the symptoms you listed. I would also check spark, as coil / coil packs can be intermittent and a bit dependent on conditions. I have replaced coil packs before, and all of your symptoms were present (with an extreme lack of power, but my coils were only firing on 2/4 cylinders).

Go the route of diagnosis. Throwing parts at it is the expensive way, and it often ends up being more work.

Would a misfire/spark bad enough to cause the engine to stall not also throw a light? Genuine question, not just being a dick lol.

When the crank sensor went on my wife’s car it had an intermittent fault for a while but never through a light for it until it got really bad.

Every obd2 computer has a misfire counter built into the cars computer. That exact number I’m not sure, key cycles also plays a role so lots of short trips sometimes won’t throw a code or it may show up as pending.

Crank and cam sensors will generally store codes for various things depending on the fault. If it’s a short/open/voltage issue or if it’s a correlation issue.

It’s always possible to have pending codes and no light, that’s why I asked if he had it scanned. Usually crank/cam sensors will always store something as it’s using that live data continuously, where as miss fires are just being monitored for if that makes sense.

There are many possibilities as to what’s causing it. Just throwing out things that are simple and common.

Thanks for the info :+1:

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I think OBD2 became standard after (2001) the build date of OPs car (1999, but perhaps some cars had it before 2001?). He should have OBD1, but I don’t have any experience with that, and can’t speak to what codes he would have. A reoccuring misfire should throw codes.

1996

As to the misfire it depends on how long he’s driving it and how bad the misfire is. Once again, just throwing East stuff out first. 130k miles on a dodge should be Atleast 3 “tune ups” in. There’s obviously a ton more that could cause those symptoms, but just going with the basics as I’m not there lol

For OBD1, right?

No, obd2 came out in 1996.

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My next random guess is a catalytic converters stopped up/falling apart causing a blockage. :joy:

Yep, you are right on OBD2. I also thought perhaps clogged cat.

One could check that by doing a temp scan after driving a while I think. You can get the infrared meters for cheap now. If it is the cat, I would go straight pipe if I was living in a non emissions testing state (due to the age and value of the truck).