Can someone advise of the correct Bosch Oxygen Sensor (pre cat) part numbers.

(i believe the LR part number is mhk000210)

The engine management light has been on and off for the last few months and the faults come up as:

02 sensor 1 heater before CAT
02 sensor 1 before CAT

Im assuming the oxygen sensors are at the end of their life at 120,000 miles and need replacing???

Last edited by Zain on 16th Dec 2018 11:23pm. Edited 1 time in total

Check the wiring is ok, you have 4 sensors so you need to know if you fault is bank 1 or 2, sensor 1 indicates it is the upstream sensor which would throw the fault but it doesn't specify which bank.
the downstream sensors don't do a lot other than check the CAT.

This is the one i purchased along with the removal tool and thread chaser as one of mine was a total pain to remove and i ended up cutting the top off and using a breaker bar and oxy torch, you might be ok..

Unplugging one or the other may help identify which is causing the problem


http://vi.vipr.ebaydesc.com/ws/eBayISAPI.d...cureDesc=0

I assumed the number 1 meant bank 1 as it states its the upstream CAT ('before CAT'). Or maybe im reading it wrong.

Are the 2 x upstream sensors (bosch part numbers) the same as the 2 x downstream sensors?


(Just googled the part number and it seems prices vary wildly from mid £40s to around £110 per sensor? Whats the catch?)

Sorry, Just checked, the one shown on my link is downstream which is MHK000220.
https://www.ebay.co.uk/itm/Genuine-Bosch-0...1712909187


The upstream sensor is
https://www.ebay.co.uk/itm/Lambda-Sensor-0...2413960236

I'm not sure if i fitted a downstream one upstream as i already had it, it may just be the length of cable but could be type of connector so get the right one.
Have a search around the net, the two above are the first two i found.

It could mean bank 1 guess, my diagnostics states bank 1 or 2 and sensor 1 or 2.

The genuine landrover part is the same as is £150 + VAT ish, below is a few comparisons of alternatives plus OEM

https://www.brit-car.co.uk/product.php/125...trol_g_cat

Thanks...thats great info.

Bosch sell on Amazon at £51.75 so i'll most probably buy the upstream sensor directly from them.

Apart from clearing down the code after fitting, does anything else need re setting?

You should be good to go once it is fitted and the code cleared.
Some diagnostics would clear adaptions and then let it relearn as the Faultmate does from Blackbox solutions and others i would guess.
This is taken from their info.

Reset Adaptation Values: This forces the engine management to reset all currently learned adaptation values to default values. The engine will run slightly rougher after this, but new values will quickly be re-learnt.


If you don't do this then I would expect it to learn anyway, see how it goes

Update: replacement sensors worked a treat, no more engine management light. The fatty feels like it drives and purrs better. (No adaptations were reset).

Now onto the next problem.....on another thread 🙁