It looks like I am going to replace all four O2 sensors on my LR2. I am getting codes P0430 and P0037. The car is 15 years old so I am not surprised I have to do this.

However, has anyone else done this, and what has been your experience with aftermarket vs. LR-blessed sensors? The difference in price is high, $400+ for a set of four from LR vs. a little over $100 for a set of four from an aftermarket company on Amazon that gives a 1 year warranty.

Also, how much work is needed to replace these? The service manual is not quite clear on this.

 

LR branded ones are just marked up Denso sensors. Get Denso or Walker sensors and save $. Usually only upstream need to be replaced. Downstream just monitor cats and tend to last a very, very long time. It could be that just your upstream are bad which causes a downstream code.

 

Ok. Are the upstream and downstream sensors the same? And how much work is it to replace them,?

 

Different part numbers usually mean different parts. Meaning it could be simply the harness length is different or upstream is heated, downstream not. I am not sure on the LR2 how they are setup so you will have to dig into that part of it. The front upstreams are harder to get at. One you can probably do from above the other upstream from below and is right behind the AC compressor and not the worst to get at. Both downstream are easy to get at.

Just make sure you use the proper tool for install. Do not torque too much, you can crack the ceramic inside. Treat them much like spark plugs in that regard and you may want to use some high temp copper anti-seize.

 

Upstream MHK100940
Downstream MHK100930

And AB sells a kit of all four, not sure which brand they are.
https://www.roverparts.com/emissions...sors/OXSENSF1/

 

Thanks!

 

Wrong model year, mine is a 2008.

 

To save money, I changed 7 sensors on my 2008 (crankshaft position sensor, camshaft position sensors, O2 sensor, etc.) all at once with a combination of new and used sensors. The less expensive ones were aftermarket and the more expensive ones were used, off of *bay. Since these cars are old school now, I also found one new old stock sensor on *bay for 1/10th of its dealer price too.

 

I replaced one of them with Denso which is the OEM for this car , but turned out it was a wiring issue , so I encourage you before paying that kind of money to test the resistance of your O2 sensors and make sure you Cat converter is good .

 

How exactly do you check if a catalytic converter is good? As far as I know all that can be done is checking the physical condition of the outside of the unit.

Wait, i found this:

To test for blockage, Access a pressure point before the catalytic converter, install a back pressure gauge and measure the back pressure. Normal reading should be less than 9 kPa @ idle and less than 20 kPa @ 2500 RPM. A high reading indicates the catalytic converter may be damaged or blocked. To test efficiency, Hold the engine speed at 2500 RPM for several minutes to heat up the catalytic converter and allow engine to idle. Using a pyrometer (high temperature thermometer), measure the temperature of the exhaust pipe around 50 mm before and after the catalytic converter. The outlet temperature should be at least 40°C hotter than the inlet temperature. If not, the catalytic converter may be faulty.

I can do the temp test, I think, but not the pressure test. Also, we have two sets of converters on our LR2s. Not sure if this test really applies.