Hi all, my names Porky, i'm in the UK, i've got a 02 Ram 1500 4.7 with 85,000 mls it runs on Gas & Lpg,it's running lumpy when cold, ( it feels like it's running on 6/7 cyl) after approx 1 mile it runs fine. I've put on a new coil on no1 cyl/ it's had 8 new Spark plugs & a new Downstream 02 Sensor, The Eng check lights on all the time, i've just turned the Ignition on & off for 7 times & the code on the Speedo was P0300, Multiple Cylinder Misfire, can anyone HELP PLEASE, Thanks very much???

 

I see you already replaced the plugs. You might want to recheck the gap. Make sure that the coils are seated all the way on top of the plugs. Make sure that the connectors are in all the way. Does the computer tell you which cylinders are misfiring or just multiple? I don't know if this'd work on the dodge. It worked for me on a ford once. It takes 2 people. Remove each coil pack and secure it so it stands on end. Put a good plug in it and have someone look for a spark to jump the gap when you try to start it. Do them 1 at a time. No spark equals a bad coil pack. I'd start with the one you know is good as an experiment to see if it even works. Maybe someone else will chime in who knows a good way to check the coils.. Good luck