bryangt
Junior Member
09 Ram 1500 4.7 w/ 249k on it.
Been burning oil for years complaining about cats and I finally did the stem seals a couple weeks ago along with plugs all around, plug wires, and lifters. She ran fine for about a week (smoke free finally) and when slowing down to a stop so someone could turn, it shut off. It threw P0306 and kept the P0420 for the cats. I swapped the coils on 6 and 2, no change. I'd put new iridiums in recently and had issues with them last time I did plugs, so I swapped back to standard coppers. Cleared codes trying to get it to give me something else to go on and got P0300 and now P0172, system rich bank 1. Found I could get it to run as long as I kept it over like 1200rpm; drove it on home the 1 mi I had left.
Since then I have replaced the cats as they needed done anyway and the 02s for good measure. I did find a broken ground coming from the rear of the engine block but could not find where it might have gone. I have since roughed up the oxidiation on it and tightened it to a screw by the pcm on the firewall.
Checking fuel pressure, it was somewhere around 54-56 and held steady through the rpm range. I did notice once I keyed off, it dropped to around 40psi slowly over the next minute or so. A buddy checked his 4.7 and claimed his pressure holds, no bleed off. Thinking I had leaking injectors, I pulled the fuel rail up this morning to look for a leak and keyed to accessory so the pump would pressurize. Not a drop. I looked for a misfire counter PID to help me narrow down like I've used before on Chevys and couldnt find one.
Heres my thoughts...
Cant be coil because its multiple cylinders; if it was it would give me p030x and follow. For the same reason, it cant be plugs or wires.
Cant be ground because its reattached.
Cant be 02s because theyre new and old acted the same. Same as cats.
Shouldnt be fuel pump because it holds pressure while running?
Intake air temp sensor shows correct temp, and only time I've thrown that code was when I was testing with the intake off.
I dont hear anything coming from valve covers to make me believe I threw a rocker.
Cam position, crank position, and map would throw other codes wouldnt they?
Been burning oil for years complaining about cats and I finally did the stem seals a couple weeks ago along with plugs all around, plug wires, and lifters. She ran fine for about a week (smoke free finally) and when slowing down to a stop so someone could turn, it shut off. It threw P0306 and kept the P0420 for the cats. I swapped the coils on 6 and 2, no change. I'd put new iridiums in recently and had issues with them last time I did plugs, so I swapped back to standard coppers. Cleared codes trying to get it to give me something else to go on and got P0300 and now P0172, system rich bank 1. Found I could get it to run as long as I kept it over like 1200rpm; drove it on home the 1 mi I had left.
Since then I have replaced the cats as they needed done anyway and the 02s for good measure. I did find a broken ground coming from the rear of the engine block but could not find where it might have gone. I have since roughed up the oxidiation on it and tightened it to a screw by the pcm on the firewall.
Checking fuel pressure, it was somewhere around 54-56 and held steady through the rpm range. I did notice once I keyed off, it dropped to around 40psi slowly over the next minute or so. A buddy checked his 4.7 and claimed his pressure holds, no bleed off. Thinking I had leaking injectors, I pulled the fuel rail up this morning to look for a leak and keyed to accessory so the pump would pressurize. Not a drop. I looked for a misfire counter PID to help me narrow down like I've used before on Chevys and couldnt find one.
Heres my thoughts...
Cant be coil because its multiple cylinders; if it was it would give me p030x and follow. For the same reason, it cant be plugs or wires.
Cant be ground because its reattached.
Cant be 02s because theyre new and old acted the same. Same as cats.
Shouldnt be fuel pump because it holds pressure while running?
Intake air temp sensor shows correct temp, and only time I've thrown that code was when I was testing with the intake off.
I dont hear anything coming from valve covers to make me believe I threw a rocker.
Cam position, crank position, and map would throw other codes wouldnt they?
