Is there no permanent cure for the Lambda sensors on the 4.2 SC.

cannot see how a person can be replacing these every 3 months when they go and cause EMS faults.

they should last for about 70,000 miles without needing to be changed out

make sure you/they fit genuine or OEM, there are cheap pattern ones out there that don't last... Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Why do you need to replace it so often - are there error codes that indicate that and what are the symptoms

@ Haylands: Thanks. I think here in SA you can only get them from LRSA.

@VNitos: New sensors were put in 4 months ago. Then last Saturday going onto the freeway the EMS light came on. Disconnected the battery and light stayed off till Tuesday. Fault was cleared on Thursday through diag tool but appeared again Friday AM. Rough lumpy idle when light is present.
This AM when I pulled the RR out you could also smell fuel. Had the error codes read this PM and comes up with P0137 and P0430.

It depends what is killing the sensors.

Is the exhaust in good condition? No leaks? Are the catalylic converters working ok?

@ Zirconblue: Will have to have to exhaust system looked at for leaks then as you say the cats.

Assuming 2 lambda sensors, are they both the same part number, if so, you could try swapping them over. I had an issue on another car once with them and it was simply a poor connection on one of them. On that car,no feedback from a sensor defaulted to 100% oxygen and so the ECU was basically assuming at least 50% flow all the time causing the car to run 'rich' on fuel (as I'm told the ECUs used to just take the readings from the 2 sensors and divided it by 2 to get the average oxygen flow rate - they may be more advanced now though). So basically , if I disconnected them both completely, the ECU assumed 100% (2 x100 / 2) air flow and the engine would run very very rich. May be worth checking the connection pins. LRs may work totally differently of course. Steve

Main car : FFRR L405 Vogue SDV8
Other car : Vauxhall Lotus Carlton
Past cars : FFRR L322 Vogue TD6 SE (Sept 2006 MY07) ; LandCruiser SWB ; 4-Runner ; Supras; XJS V12 LeMans

@George. What error codes does it show when you plug the diagnostic tool in. Does these errors include "multiple misfires"? Is the car's engine performance reduced when the EMS light is on. Is the lumpy idle a misfire or not?

Reasons for my questions is that there is a known problem with the 4.2SC's auxiliary cooling (water) pump - LR connected the wires the wrong way round resulting in the pump turning the wrong way round with resultant failure of the pump.

I have a problem that when my car is idling the body shakes like it is misfiring. However the car always performed well. I removed the cats and replaced spark plugs which improved but not completely cured the problem. So I'm going to have the auxiliary water pump replaced within the next week or so.

If you pm me your email address then I can forward you the TSB that LR issued re the water pump problem

@Trev PM sent.

codes P0137 and P0430.

Idle is rough and lumpy with light on

there is the possibility of a missfire as the idle even with light out is not a continious humm but an up and down afair.

So took the truck in to an Indie past Friday. They hooked up the more upmarket OBD tool and picked up a low voltage error on the rear sensor for bank 2. Swapped right to left and cleared all errors. So will monitor the new setup and see if error returns.

Did this also resolve the lumpy idling issue?

I would say yes; but did not drive too much this past weekend. But on startup yesterday; this AM and this arvie I did not notice any lumpyness or roughness on start-up at idle speed.