You've confirmed the O2s themselves, the wiring to them, and the Catalytic convertors they use are functional. Next, you're going to want to look for things that'll cause fuel to burn wrong (vacuum leaks or air flow measurement issues, fuel flow thru injectors, or coolant leaks in cylinder heads), or the systems that control those things (computers). The order I listed them in is a pretty good way to start, hope it helps.

Also, did you get the Rave manual downloaded yet? It's pretty helpful for finding your way around this British marvel of engineering...

 

I do have the Rave manual. Does it have detailed diagnostics to help with this kind of stuff? Also I do know that there is a high pitched squeaking noise that after months of replacing belts I found that it was high pressured exhaust coming from the bottom of the manifold where it meets the cat on both sides. I haven't checked there yet after I installed the new cats but the noise is still there. I was surprised because I put new metal gaskets between them before I installed the new cat. Is it a vacuum leak only when un-measured air is coming into the engine or is it also a vacuum leak when exhaust is seeping out the bottom of the manifolds where it meets the cat?

 

That would not be a vacuum leak, but that would qualify as an unmetered air leak into the object that is measuring air/fuel burn. So yes, it is possible that might cause mis-readings from the Catalytic and the O2s if the leak is before the Cat....

 

Yes, on a different vehicle I was surprised to learn that an exhaust leak can cause erroneous O2 sensor readings. I had previously thought that exhaust would only leak out, but I learned that enough fresh air will also leak in to cause an incorrect reading.

 

So I decided that I'll make some copper metal gaskets for the bottom of the exhaust manifold and the top of that cat. That way they are more moldable to the mounting surfaces and heat transparent. I feel the ones on there don't seal well because of the weird lip on the edge of the gasket. I'll also get an exhaust flange clamp from auto zone in hopes that I can bolt and seal them together more efficiently. Hopefully both of those things will help eliminate the exhaust leak that I have on both of them. Checked last night with soapy water while the car was running and there is definitely some leakage out from where the gasket meets. Do you guys think that is a good idea? Any other thoughts on what I can do?

 

I have the EXACT same P0160. New sensor shows the same. Swapped both rears shows the same. Disconnected the sensor completely and live data still the same .445v as before.

Did you solve your p0160??

 

I actually never ended up installing the copper gasket with the additional clamps. After taking the car to a tailpipe emissions test, the individual said that my emissions was cleaner than they've ever seen before with a vehicle that old and all the numbers were running correctly. That's probably because I installed new catalytic converters hoping to solve the problem. I've come to realize that it very well could have been a small CO2 leak from where the squeaking noises coming from. But I actually believe that it was a malfunctioning engine control module. My wife and I decided that it wasn't worth continuing to dump money into it every month. So we ended up selling it and used that money on a down payment for something more reliable. Sadly I truly miss that off-road legend, but at this point in my life I decided to get something that I could trust for my wife to drive. Hopefully you figure out what exactly the problem would be for you without it being too expensive. Best of luck to you.

 

Oh okay wow! Yeah it's funny because mine actually Burns very clean also. Runs really strong probably the most power that 4.0 ever put out and it's at 174,000 Miles haha! So I guess I will just search for any type of exhaust or vacuum leak. I actually took it for a test drive with live data and now that bad side is reading fluctuating vaults but now pull us up a code for 02 heater circuit rather than no activity detected. I'm one of those weird people about not wanting to check engine light even when it's running good. I own an lr3 with a 4.4 Jag and so far it's been amazing but gosh those electrical Gremlins that come with the rest of that thing sometimes drive you crazy until you learn that it's pretty much all based on the battery and the alternator. Well thank you anyways I appreciate the response.