Dtc P1391. 2002 ram 1500
 

2002 ram 1500 4x4 with the 4.7 and 179,000 miles cel came on truck was running like hell, felt like rear ended coming out from under it, pulled the codes and only code was 1391, replaced cam position sensor, drove a total of 35-40 miles light comes on, same code, crank sensor was replaced last year. Truck runs great. Light was on a few weeks before it acted up. Should I have put the electrical grease on the plug? It did look damp/ wet when I unplugged it. Bought the sensor at orileys and crank sensor I believe from autozone. Any ideas?

Can I spray a degreaser in the plug or brake parts cleaner then use dielectric grease? Would the inside of the plug being damp cause intermittent loss?

Not sure on the newer trucks.... but.... the older fellers REALLY don't like aftermarket sensors in critical locations. They just don't seem to give the proper signals. I would be tempted to pick up genuine mopar sensors, see if that didn't improve its attitude.

Could dampness in harness cause it

Possibly.

I just picked up some dielectric grease, also I didn’t unhook battery before installing, was in a hurry since it was -12 but it’s unhooked now just waiting to hook back up

Light came back on just by letting it warm up

You can try resetting again, and see what happens, but, if it comes back, I would be real tempted to replace both the cam and crank sensors with genuine mopar pieces.

The cam sensor fixed the issue I was having, but I will be replacing crank sensor today and getting the grease in the pigtails, supposed to warm up here today instead of this - temps

Light back on, I’ve replaced both sensors, was out for about a week then back on, same p1391 code

Are they both mopar sensors now?

Neither are, it’s developed a miss when it’s cold now, and hesitates

You really want mopar sensors in there....... the aftermarket fellers just don't work as good.

After it runs about 6 or 7 minutes the miss disappears and runs great, so I don’t think it’s related to the sensors to be honest

Have you checked fuel pressure? Wonder if it is a bit low, and when the truck goes into closed loop, the O2 sensors compensate?

Well it started messing up real bad today after sitting for a few hours, I didn’t let it warm up just jumped in and went and it was terrible, so I pulled over, used a code reader(p1391) same as before, cleared the codes and it ran fine so I would rule out fuel pressure

I got some freeze frame data, the short term fuel was at 0 and long term fuel was at -3.1 when I get code, I accidentally erased the reader so now I have wait till it happens again

Hhhmmmm...... Are you still getting the 1391 code?

Need to address that.....