2004 5.7 Hemi P0300 Multiple Misfire
Champion
Joined: Aug 2006
Posts: 4,489
Likes: 4
From: New Jersey
i have a 05 dodge ram with the 5.7 hemi in it, the truck has a rough idle but it smooths out after driving it amd its hot. i used sea foam to clean out the fuel system, ive done plugs to it (e3) and egr valve. im getting a p0300 misfire code and a high voltage 02 sensor. i check all the plugs oon it and they seem fine. also misted the coils to see if any of the coils where getting moisture in them but nothing. also checked the crankshaft sensors and both are reading dead on.
Change to Copper Core Plugs and Replace the O2 sensor that is giving you trouble, also make sure your spark plug gap is within .02 of the indicated Gap in your owners manual.
Registered User
Joined: Sep 2013
Posts: 1
Likes: 0
I assume youve fixed this already, but my 07 also threw a p0300, had a slight misfire or two and at the same time a p0339 " crankshaft position sensor intermittent" code. I replaced the crank sensor and haven't had the issue again.