Trying to pin point this issue. When these codes popped up my exhaust started sounding like there was a leak. I also smell exhaust while driving and its pretty rough at idel. Any suggestions?

 

Could be several things. Bad or cheap o2 sensor. If you have a valve cover leak you'll kill primary aka upstream o2 sensors. These are usually the culprit.

next is an air leak. Upper/lower intake gaskets, leaky valve covers,, vacuum hoses etc.

A falling maf could cause it.

Clogged cat, exhaust leak.

Back injector seals or bad injector (s)

I'm experiencing similar codes in our 99, I'm pretty sure I've narrowed it down the the maf.

 

Wow, okay, well my valve cover bolts where super loose. I tightened them the other day really good. Now I’m wondering about exhaust leaks

 

Update: Did a reading on the volts yesterday and found that all sensors read .450ish but B1S1 is at .065.

 

Did you ever find the fix for this? Brand new Disco owner and had these codes come up the second day I had it. I’m very new to land rovers.