O2 sensor code 21
#12
#13
Was there a HD 5.2 in 94-5? According to my 96 fsm it was only the 5.9 that was HD. Not sure if the vin sequence is the same but the 8th digit is for the engine. Z is the standard and 5 is HD. If you swapped in HD pcm you will need the harness for it also due to the extra 02.
Ok. I was not sure whether the HD pcm wanted a second o2 or not. The problem I face now is the harness. I don't have, and it is very hard to find a 5.9 gas HD harness.
But here is an idea, just want to see if in theory it would work:
The heater circuit in place on the harness for the single o2 sensor is the same, as well as the sensor ground. Would I be able to tap into the existing harness for the right o2 to get the sensor ground, and 12v heater circuit for the added left bank o2? And then run a single wire to pin 23 on the pcm connector?
My concern lies in the heater circuit. Tapping into the existing sensor ground for the right o2 should be fine, but would the guage of the wire running from the ASD relay to the existing o2 connector be able to handle the amperage of another o2 sensor? As well as the heater circuit ground? I'd rather not melt my harness and send the truck into flames.
Like I said, in theory "I think it should work" (famous last words) , but wanted to get y'alls opinion on it.
#14
I wouldn't even bother with the second sensor. Just tap the signal feed wire from the existing O2, and feed that to the pin for signal for the second sensor. PCM gets what it's looking for, and you don't have to worry about much additional wiring.
Something else to consider: It may be cheaper/easier to just get a PCM for a standard magnum engine......
Something else to consider: It may be cheaper/easier to just get a PCM for a standard magnum engine......
#15
I wouldn't even bother with the second sensor. Just tap the signal feed wire from the existing O2, and feed that to the pin for signal for the second sensor. PCM gets what it's looking for, and you don't have to worry about much additional wiring.
Something else to consider: It may be cheaper/easier to just get a PCM for a standard magnum engine......
Something else to consider: It may be cheaper/easier to just get a PCM for a standard magnum engine......
I have the 5.9 gas, that never had a manual behind it in the half ton. I have the only pcm that came with the 5.9 gas and manual, in the 3/4 ton/1 ton. So I have to have the pcm I have. I'd rather not run the 5.2 pcm and run the motor super lean. I don't see another option than screwing with the wiring.
#16
There should be an option for a 5.9 and a manual with the standard duty engine as well. After all, they were far more common than the HD version. (basically, a commercial vehicle)
The O2 sensor just reads oxygen in the exhaust stream. it expects a certain amount, which results from a stoich mixture. (14.7:1) If you feed the same signal to both sensor inputs, from one sensor, the PCM will simply assume that both banks are running at the same ratio, and adjust injector pulse-width accordingly, just like they do with only one sensor.
The O2 sensor just reads oxygen in the exhaust stream. it expects a certain amount, which results from a stoich mixture. (14.7:1) If you feed the same signal to both sensor inputs, from one sensor, the PCM will simply assume that both banks are running at the same ratio, and adjust injector pulse-width accordingly, just like they do with only one sensor.
#17
Ok. I'll be heading to the scrap yard tomorrow to get a pin for the pcm connector so I can insert it into mine, as well as getting some connectors to make a jumper harness so when I jump off of the signal for the o2 sensor, I don't have to ruin my origional harness. I hope tapping into this single o2 will work.
I also have a question relating: how have some of you guys gutted your cat? Mine has 2 inlets and one outlet, do I need to cut the outlet and one inlet, or how have y'all that have done it? Mine is plugged and I need the lost power back.
I also have a question relating: how have some of you guys gutted your cat? Mine has 2 inlets and one outlet, do I need to cut the outlet and one inlet, or how have y'all that have done it? Mine is plugged and I need the lost power back.
#18
#19
So today I got to the scrap yard to pull a wire and pin for the pcm connector, I also made my jumper harness so I could splice into the sensor signal. I installed the pin into cavity 23, plugged in the jumper, routed the single wire in conduit to the jumper, spliced them together and took it for a drive. After 10 minutes no more CEL and runs a lot better, especially at idle. Thanks for all who helped, especially hey you, otherwise I'd be more money into exhaust for a second o2. Fixed the issue for only $2.9 from the junk yard!
#20