ok here is something I have noticed and I'm pretty sure its what is causing my [UPDATE] codes I have are 133/134/155 on the UG .. ( Ill have to check to see specifically if these are the codes but Im pretty sure.. its an O2 issue on one side.. anyway... here is what Im getting... when I fire up Disco first time... the drivers side upstream bank sits at .445 or something until warm and normal SAI goes off then switching numbers on Ultra Gauge for O2 occurs... on the passenger (USA) side upstream on startup it goes to 0.000 on startup and throws these codes... Im thinking this is a specific SAI solenoid or something causing this? after warm up I can clear codes and unless its a cold cold day or SAI comes back on or I let car cool off, I don't throw the codes... .hmmmm anyone know about this system enough maybe knows exactly whats wrong hu?? anyone? bueler... bueler... bueler....

[UPDATE] the codes I have are 133/134/155 on the UG ... not what I put up top earlier.. so I changed in original message also

 

I can see everyone hates SAI teching lol

 

so I don't know more than the basics of sai. but it seems that you have an o2 issue and don't see the connection. sensor has heater to activate itself. doesn't seem to be working. I don't see how the extra pumped air from the sai can change it.
but I have a disclaimer

 

Once warm, does the passenger side stay at 0000?

 

NO once warm all goes to normal... its just at initial warmup and anytime the SAI pump comes on.. the passenger bank goes to 000 maybe 002 or something but acts as though too much air getting in and making it go rich... its a new Atlantic British O2 and a second replacement over 3 years... I even switched the banks from left to right and problem stayed on passenger side Bank 2 I think it is but Im still confused which bank is what lol ... I kn ow front is 1 and rear is 2 and left n right Im not sure of orientation on the ultraguage and what land rover calls left n right lol anyway... problem stays on that same side and only during time Sai is running ....

 

Cold day in West Palm Beach? What's that, like 55 degrees?

The only difference between banks that can be related to SAI is if one valve works and one doesn't. Once the SAI solenoid activates, it sends vacuum to both valves through the same line. If one valve is stuck then it won't open when vacuum is applied and the air from the SAI won't be fed into the exhaust on that side. Do you have a hand vacuum pump available? You could use it to try to open the valves when the engine is running and warmed up. Disconnect the hose from the SAI pump to the valve then try to open the valve with the vacuum pump. If it works, you will hear and feel exhaust coming out.

 

Now we are getting somewhere. If the O2 starts switching after the SAI get goes off, then the SAI is the issue. Like 04duxlr says, check the valve. Unfamiliar with the system because my Rover is sans SAI, but honestly, it's not that difficult to figure. Out. It's a air pump that adds air to the exhaust to heat up the cats. And it's virtually the same for every manufacturer. Different design , but the concept is the same.

 

just made changes to my wording lol I meant to say it goes to normal after pump goes off... so I changed my wording above to answer correctly that NO it does NOT stay at 0000 after SAI goes off... it starts switching normally... also at first startup it doesn't just 000 out.. it slowing over about 30 seconds just drops in numbers until it 000 out then Sai goes off and it starts switching normally

 

P0135 is a heater code, and won't be affected by the SAI... It means there is something wrong in the O2 heater circuit.

 

yeah... I knew that but if the SAI is causing a rich or lean mix for an extended amount of time wouldn't have I have weird O2 codes?