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Discussion Starter · #1 ·
Not sure if anyone has posted this problem before, if it has...sorry for the re-post. So yesterday I start the truck up and leave the house...a few miles down the road it starts to sound almost like an exhaust leak and I lost some engine power. The engine light came on so I checked the code and it was P0302 Cylinder 2 misfire. So I start with changing the plugs, problem still there. Then I changed the coil pack, problem still there. Then I changed the fuel injector, problem still there. Between changing the coil pack and injector I took my truck to a friends shop and did a compression test which turned out to read the same as cylinder 4 & 6. We also hooked up those noid fuel injector test lights to see if the connections were bad. So now I am here and run out of ideas. I have read a lot of "diagnoses" online but I'd rather ask people who might have had this happen before or know someone that has. Please help...running on 7 cylinders sucks!!!

Thanks! :smiley_thumbs_up:

2002 Ram 1500 Crew Cab 2WD 4.7 V8 Automatic
 

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I get brand new parts that are bad at work every week. I have no idea what happened to quality control.

I realized that in your original post. Try resetting the ECM. Unhook the battery, cycle the key once, and hook it back up and try it.
 

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Discussion Starter · #6 ·
I get brand new parts that are bad at work every week. I have no idea what happened to quality control.

I realized that in your original post. Try resetting the ECM. Unhook the battery, cycle the key once, and hook it back up and try it.
Would resetting the ECM actually fix a misfire? I can understand maybe clearing the code...which I already did. I guess I can give it a shot...what could it hurt?:4-dontknow:
 

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I have to agree with WarlockIII on the test procedure. Swap the plug, coil and injector with 3 other cylinders. Even though you have new parts, swapping in 'known' working parts is more definitive. An ECM reset never hurts. I have never come across an ECM issue of 1 bad cylinder fixed by a reset, but it is a computer so anything is possible. I have however seen an ECM throw the wrong code for mis-fire. Usually it's a cylinder beside in the firing order, so in your case 1 & 7. :4-dontknow:

After this, you may have to remove the valve cover and check the valve lash and throw on the cylinder. If a valve is not opening properly, a mis-fire could develop that is RPM/power demand related.
 

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Have seen a similar issue on a different engine that turned out to be a bad ECM. The one channel for that cylinder was the only thing effected. I dont know enough about the ECM in the 4.7L to say if thats possible in this case or not.

4.7l is known for getting carbon build up on the valve stem which causes the valve to stick and the rocker arm to pop off creating a dead cylinder.
 

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I have the same problem on cylinder 2 but i have the 3.7 V6 I have changed the coil, fuel injector to a diffrent cylinder and even the spark plus after i have changes them all its not knocking but there is fuel build up on the cylinder 2 sparkplug i also have replaced the cat still a misfire runs smooth at 2000 RPM and abot 65 MPH misses bad on take off and hard to hear on idle what else could cause this
 
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