I'll verify the check valves in the next day or so; the last time I was under the vehicle the canister looked intact, as did the lines going to and from it but I'll check again.

Also I'm going to check the voltage on the 1/1 O2 sensor on a cold start and see what the voltages are reading according to the PCM. Additionally, I have, literally, 8 other NGK O2 sensors (long story short when I re-did the wiring harness I mislabeled the O2 sensors and kept getting codes and silly ol me thought I could solve the issue by throwing money at it), is there a procedure in the service manual to bench test O2s to verify functionality prior to installation? I figure if my sensor is really going out, one of those 8 have to be in okay condition?

 

No way to test O2 sensors without specialized equipment..... Basically, they either work, or they don't..... with some interesting stuff in between..... I would imagine you could test resistance across the heater circuit, just to verify it isn't open.... but, that's the only test I can think of you can do at home.

 

Sorry for the delay in testing, the last couple of weeks were quite busy.

1. I verified that both check valves are working and installed in the correct direction.
2. Checked for a vacuum leak by spraying starter fluid around intake manifold and along vacuum lines, didn't notice any uptake in RPM.
3. Somehow, without me resetting the PCM, the P0135 code has seemingly disappeared. Drove for about 50 miles with no CEL and all of a sudden P0132 popped up for about a day or two and is now gone with no CEL or pending/stored codes on my scan tool.

Really don't know what to do next, I'm considering taking it into a shop but I don't want to shovel out hundreds for diagnostics as I'm assuming it'll take them a while to find this gremlin. Part of me thinks it might be a PCM issue since the PCM in the truck has definitely been flashed/tampered with in the past. It has "2000 Dodge Ram Truck 5.9 Gas Auto 410 AB" written on it in what appears to be white out and IIRC the version of software on the sticker is potentially outdated.

 

Hey all,

Fiddled with the truck more last night and realized that the check valve going to the cruise control was oriented incorrectly, I now have cruise control (finally!) and it appears as if the rough idle after 30-60 seconds is seemingly gone but we will see about that. On the other hand, I now have concurrent P0132/P0135 codes. I'm going to swap sensor 1/2 to 2/2 and vice versa to see if the codes follow the sensor, as of right now I can't think of anything else. Just really confused as to why all of these O2 codes are so sporadic.

 

So I swapped sensor 1/1 to 2/1 and vice versa, seemed fined for about 300 miles and now I have the same P0135 code for sensor 1/1. I guess my only option is to double check (again...) the continuity on the signal wire as well as the voltage when running. Is there any additional data I can get, such as from my scan tool, to help me diagnosis this? Or at this point should I just take it in somewhere and run them through what I've done. It's seeming more and more likely that I have an electrical issue (or some other gremlin) as I didn't get a code for sensor 2/1 after the swap.

Additionally, I've noticed that the CEL only comes on after the truck has been sitting and I start it up in the cold morning weather. Before parking it last night I literally checked for pending engines codes and there were none, then suddenly on start up P0135 is there again. Not sure if that's helpful or not but figured I'd include as much info as possible.

 

Check resistance of those wires as well. High resistance will show continuity, but, greatly effect the readings the sensor feeds back to the PCM.

 

Hey all,
Still been dealing with and trying to sort out this issue in the background. Long story short, found a great local shop that built some suped up versions of these trucks for SEMA back in the day and had them run through everything to ensure I didn't do something incorrectly during my lengthy diagnostic. After all of this, they confirmed what I'm making good vacuum, have good compression, fuel pressure, continuity with sensors, so on and so forth. Their suggestion was to get the PCM tested as during multiple system tests, random components such as the brake light switch, ABS system, o2 sensor heaters, etc, continually cycled from "ON" to "NO DATA." My timing and fuel sync were set correctly as well.

Anyone have a particularly well regarded website/shop that I can ship my PCM to for diagnoses/reprogramming? I ordered from FlagshipOne in the past but literally never received my order and eventually got a refund from them, so I'm guessing that isn't a company ya'll would recommend.