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I realize that I accidentally made several posts. Could anyone that replay use this one. I have marked the others and hopefully admins can remove them. Thanks!
Hello all. I have been watching the scannerdanner videos and scouring the internet for any info that may help me diagnose my issue. First let me give a little back ground info.
So last year was eventful for my truck. 08, SE, 4.0, 4x4. It started off with some weird stumbling when it got hot. Then turned into no start when hot. I tried all kinds of things including new plugs, new injectors, new camshaft, and crankshaft sensors. Couldn't figure out the issue. Of note I never had any codes during this time frame. Then the engine sprung an oil leak on the passenger side valve cover. The leak started off really small and then all of a sudden went very big quickly and caught fire. This burned my wiring harnesses on the passenger side. Parts burned included the upstream o2 sensor(bank 1 sensor 1), crankshaft sensor, and knock sensors. I was able to repair the wiring and the valve cover. Go the truck started but with SEL and codes. (codes to follow) The truck ran for about a day and then died again. After help from the Nissan frontier forum was able to determine that the primary cats were clogged, as well as dissolving into the secondaries. This was the root issue of the hot start and stumbling issue. I cleaned up the secondaries and replaced the primary cats with some cheap ones. Still had SEL and codes. About a week later I experienced the dreaded radiator/transmission failure and got coolant into my transmission. I did the bypass and tried to flush all the water out. I put roughly 12 gallons of transmission fluid through it. All seemed well and then about a week later the transmission completely went out. I have finally replaced the transmission with a used one that I found and the truck is currently running and driving. However, I still have the SEL and codes. The engine runs ok, but pretty rich and I feel like it's a little low on power. I am getting terrible gas mileage as well. Codes as follows:
P1148 Manufacture Control
P0032 H02S Heater Control Circuit High Bank 1 Sensor 1
I have been trying to diagnose and fix this issue for several months now. I am fairly certain that when I fixed the harness I didn't cross the wires because I went back and checked and rewired using solder and heat shrink tubing to assure good connections. Additionally, I replaced the burned O2 sensor with the correct Denso sensor. I am running the same sensor on the bank 2 side of the engine without codes. So for this is what I have done for diagnosis.
1. Checked the fuse. It was good. (also unlikely to be fuse as it also runs the other O2 sensors and I don't have codes for them)
2. Checked the sensor heater sensor for resistance. I get 2.3 ohms which is the 1.3-2.44 ohms range per the service manual.
3. Checked the harness heater power wire for power, and it gets 12.03 volts with the key on. The Manual says battery voltage so this seems to be correct.
4. Checked the harness ground wire for continuity and short to ground. There is continuity with a reading of .3 ohms. No short to ground found with testing with a test light.
5. Using a backprobe/t-pin I checked the voltage on the load side of the sensor with the key on. I was 12.03 volts as well. This would indicate that the heater sensor is good as well and matches the resistance test. Additionally, this appears to be a ground-side switched circuit. So with the key on and the engine off the circuit should not be activated and 12.03 volts is an accurate reading.
6. With the key on and the engine on, the voltage jumps to 13.5 or so on the load side. I also believe this to be a PWM-type circuit. Not sure what the reading should be here.
7. Repeated all the same tests and readings on bank 2 sensor 1. All readings appear to be the same as bank 1 sensor 1.
8. I used a clamp on an ammeter to measure the current of the two sensor wires on bank 1 sensor 1. It showed.9 amps on startup and after 10 seconds it drops to .03-.1 amps. Readings on the bank 2 sensor 1 show 3.9 amps on startup and then drops down to 1.5 amps after about 10 seconds.
There appears to be something that is causing an amperage difference between the 2 sides. This seems to be the issue but I don't know where to go from here. Again I don't think that I got the wiring wrong. When testing the harness the 12volt power wire is in the correct location as per the manual and verified on the multimeter.
