O2 Heater Codes

[Mercury]

The engine has to be running or the ASD relay will not close. Testing for voltage you should not damage anything and yes you can check the heater inside the sensor with the Ohms setting but I don't know what the value would be, but at least you can verify that it is not open. If there is no power on the two heater wires try checking from hot to the frame, then if you see power you'll know it's a bad ground, otherwise it's the hot side. Might be a good idea to verify your engine to frame ground anyway.

Update: Advance Auto offered to warranty exchange the O2 sensor. While I normally don't like throwing parts at a problem this seemed like an easy test for no cost.

At cold the codes were gone. Once I hit operating temp I got the high voltage code from bank 1 sensor 1. So now the heater code is gone but still getting the high voltage.

 

[B1Toad]

The high voltage indicates the sensor is not getting warm enough, when it warms up the voltage should drop. Maybe try switching the two sensors around and see if the problem follows the sensor.

 

[Mercury]

The high voltage indicates the sensor is not getting warm enough, when it warms up the voltage should drop. Maybe try switching the two sensors around and see if the problem follows the sensor.

Since the new sensor has the same issue would switching the sensors accomplish anything? Also since they are different models of NTK would that make a difference?

 

[B1Toad]

I don't really know. Sometimes parts are finicky and I have learned to have little faith in box store parts, I always shop at the local jobber warehouse or a dealer. For my Powerstroke and my Sprinter I have found online dealerships with good prices, have not yet looked for one for Jeep yet. Our local dealerships are really expensive.

 

[Mercury]

I don't really know. Sometimes parts are finicky and I have learned to have little faith in box store parts, I always shop at the local jobber warehouse or a dealer. For my Powerstroke and my Sprinter I have found online dealerships with good prices, have not yet looked for one for Jeep yet. Our local dealerships are really expensive.

Agreed. I don't trust them either. I just go with the NTK O2 sensors because that's what they recommend on the forums. Well, it's what the forums have said is the only one to use.

So it's possible I'm still not getting enough heat to this sensor, then. Okay, I have a video on some testing to do with a tester light that I'll play with.

 

[B1Toad]

The funny thing about name brand parts is that due to competition they have different ones, for instance Motorcraft has rotors for my Ford with 2 part numbers, they are identical except for price and the cheaper ones are made in China while the more expensive ones are made in Mexico. Same with Timken unit bearings, Autozone had two part numbers for my Chevy Express, both Timken, both identical, but $200 for Chinese and $400 for Mexican. Their computer database didn't say China or Mexico but when we got the boxes out on the counter and examined everything that was the only difference.

 

[Mercury]

Turns out it was that section of wiring. One of the wires I had crimped had come loose, so I just cut them all off and started from scratch using heat solder butt connectors. Everything works now.

 

[B1Toad]

Turns out it was that section of wiring. One of the wires I had crimped had come loose, so I just cut them all off and started from scratch using heat solder butt connectors. Everything works now.

Great! Keep an eye on those heat melt butt connectors, they have a fairly low melting point, are they above and close to the converter?

 

[Mercury]

The cat? What cat?

I didn't realize that with those connectors. I have them pinned as far from the engine/intake as possible up against the firewall. I'll order some heat-resistant wire loom and hope that it offers some protection.

 

[B1Toad]

The cat? What cat?

I didn't realize that with those connectors. I have them pinned as far from the engine/intake as possible up against the firewall. I'll order some heat-resistant wire loom and hope that it offers some protection.

If they're in the engine bay they will probably be fine, I though they were down by the cat. You could wrap them in engine harness tape then put split loom over that. I use this one: https://www.amazon.com/dp/B01I2MLN2Q/?tag=wranglerorg-20 Wrap each one individually then wrap them all together.

 

[Mercury]

Tessa High Temp tape and some loom.

How about this instead of the loom?

https://www.amazon.com/gp/product/B09VV59SWZ/?tag=wranglerorg-20

 

[B1Toad]

I haven't seen that stuff before but do they mean it will hold up to the heat or will it protect the wires from heat? Doesn't seem like it would protect the wires with the free air flowing design, I think whatever you put in it needs to be heat protected first..

 

[Mercury]

I haven't seen that stuff before but do they mean it will hold up to the heat or will it protect the wires from heat? Doesn't seem like it would protect the wires with the free air flowing design, I think whatever you put in it needs to be heat protected first..

Hmmm. I thought it was to protect the wires but good question. It looks just like the stuff that comes on the O2 sensor itself which is made to be close to the exhaust, but I can't find anything online that confirms it protects the wires.

I imagine it protects from accidental contact but I don't know how much else.