I have a 2006 ram 1500 4.7L v8 4x4. Had a code for upper bank O2 sensor bank 1. Through a code for the for random misfire and crank shaft position sensor. So I changed the O2 sensor and the crankshaft position sensor. Got about 5 miles down the road and truck started to misfire bad and engine light came back on. Had it scanned again and gave p0300(random misfire) and P0339(crankshaft position sensor) the one I purchased was aftermarket OEM so I ordered a new one from the dealer. I installed the new one and followed the wires as far up the harness as I could looking for a short(found none). Got half way up my street and engine light started flashing again. It has a slight misfire that I can feel in the peddle and light will go away or stop flashing when I'm at a stop. But as soon as I give it some gas it will return to flashing the C.E.L. I have read it could be a flat in my EGR valve but not getting any codes but crankshaft sensor and generic misfire code. The truck is not stalling out but fuel economy is tanked bad. Anyone with some experience with this issue that can shed some light on where to turn next? I would greatly appreciate it

 

What brand O2 sensor did you get? Did you replace both front sensors, or just the one? (are there two on yours???)

 

There are 2 front O2 sensors. Denso is the brand. I only changed the driver side.

 

Change the other side as well. Stick with the Denso sensors.

 

Will do. So this doesn't sound like an EGR valve issue or the crankshaft sensor?

 

Might be EGR yet, but, change the O2 sensor first. See what happens. If the two sensors are giving radically different messages to the PCM, odd things happen.

 

Changed out the other o2 sensor. Got about 1/2 mile down the road and light come back on. Now scan says 3 p0300 codes. Nothing with the crankshaft sensor. Going to change spark plugs and see if that's the issue. Herd copper was the way to go on this truck. Baffled so far. Idle is between 600-700rpms and don't feel hardly if any hesitation in acceleration. But I purchased the truck used and do not know if plugs have ever been changed

 

Was not the plugs. Had platinum plugs in it. Looked warn across all 8. Still throwing the CEL when I am accelerating. Goes away when stopped.

 

Reset the pcm. Just disconnect the battery, turn the key to start once, then back off, reconnect battery. Go for a drive, see what codes come back.

 

So I reset the pcm. Took a drive. Light come right back on. Still only showing the P0300 code. Guess it is time to change the egr valve and see if that resolves the problem. I saw a thread somewhere where someone with similar issues said they changed the egr and crankshaft sensor and had luck but can't find the post. Could have been a dream🤷*♂️🤦*♂️