Looked around online and can't seem to find the answer I am hoping for, so figured I would ask here. I have a 96 D1 NAS V8 with two banks of O2 sensors. I replaced the first bank with brand new and the engine runs great, but my check engine light is still on showing bank 2 fault in O2 sensors. Now bank 2 apparently is only to check if the cats are working, which they likely arent working good enough after all this time that I am worried about replacing bank 2 sensors that the light will stay on for a new reason. Also, I dont want to spend 300 bucks to turn a light off that doesnt actually affect the car. I was wondering if anyone has gotten around this? Can I make a splitter cable to give the signal from the front sensors to all 4 O2 wires? Is there a way to program the ECU to only recognise the front 2 like some of the V8s from other markets?

Any help appreciated! Otherwise I will just live with the light on.

 

Let's make sure we are all using the same lingo. Bank 1 is the left side of the engine, supporting cylinders 1,3,5,7. Bank 2 is the right side, cylinders 2, 4, 6, 8. Sensor 1 is the upstream sensor before the cat. Sensor 2 is the downstream sensor after the cat. So, for example, Bank 1 Sensor 1 is the upstream O2 sensor on the left (sitting inside the truck perspective). B2S1 (bank 2, sensor 1) is the right side sensor before the cat. Using this terminology will also help interpret the codes correctly.

Both downstream sensors (B1S2 and B2S2) are unplugged on my '96 and the truck runs fine, but does throw a code. I tried fooling the ECU by installing resistors in place of the downstream sensors, but the ECU is smart enough to know that a constant signal is no bueno, so still throws codes. I guess sending the front signal to the downstream sensor will still throw a code because that really is the definition of cat inefficiency (downstream signal equals upstream signal).

 

Thank you, my terminology was definitely incorrect ( I was referring to upstream as bank 1, and downstream as bank 2). And interesting, so that kills most of my ideas for fooling the ECU. Sounds like I may have to live with the light on...

 

John, you may be able to get rid of your code by simply plugging a pair of O2 sensors in and tyrapping them out of the way.
Weekend warrior, I’m assuming that you cleared your fault. I don’t think the light will go away until it’s cleared.

 

Correct, Ive cleared multiple times and comes back. My concern is that if I replace the O2s my cats are probably no good and the light might stay on anyways... was hoping to fool the system but sounds like they thought of this. They cant get sun roofs not to leak but they can keep us from defeating emissions.

 

A bit of electrical tape will take care of the light on the dash. Just make sure you know what the code is and scan occasionally for other codes. On some vehicles, the CEL will keep the cruise from working.

 

That is an interesting tid bit, considering I tried to get my cruise to work and could not figure it out. This might be why. I did end up pulling the bulb for the ABS considering I deactivated it, but ill probably just replace the sensors at some point to clean up the light.