DIY LR3 catalytic converter replacement - how difficult?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Ulf001

Member
Joined
Jan 3, 2013
Posts
9
Reaction score
6
My 2007 LR3 with 135,000 miles is throwing P420 and related codes. I have been told by a Land Rover mechanic that it's not the O2 sensors as I initially suspected, but the catalytic converters are in fact bad, and will need to be replaced to get the check engine light to stop coming on. Was quoted $3,600 to swap out both cats. The job does not appear to involve welding. Has anyone done an LR3 catalytic converter replacement themselves? If so, how difficult was it? How long did it take and what sort of challenges were involved?
 

DaytonaRS7

Full Access Member
Joined
Apr 7, 2020
Posts
589
Reaction score
304
Location
11743
Its not the correct fix, but have you considered adding o2 sensor spacers? its a trick people with no/or high flow cats use to trick the ECU into thinking the cats work properly. Essentially limits the exhaust flow that gets to the sensor.
$20 and 30 minutes of your time.
 

Ulf001

Member
Joined
Jan 3, 2013
Posts
9
Reaction score
6
Thanks for the suggestion. I was not aware of such a product. Sounds like that might be a good option for me, at least until I unexpectedly stumble into a vast fortune and can get the cats replaced.
 

DaytonaRS7

Full Access Member
Joined
Apr 7, 2020
Posts
589
Reaction score
304
Location
11743
keep in mind this fix is technically not legal. If your car is subject to safety inspection, and the shop actually does a thorough job and cares, they could fail it for this.
If the shop simply plugs in the scanner and sees there are no codes, your good to go <--- this is what most shops do.
 

catman

Full Access Member
Joined
May 4, 2015
Posts
699
Reaction score
194
Location
The Relay Shack, Parts Unknown USA
Do you have a code reader and has the light been reset? It sounds like you have but I am just checking, I had this code pop up once on my 08 LR3 with 170K while on the highway, I used my IIDTool to reset it (an Ultraguage or similar will also work) and it has never come back on (about a year and 10k miles anyway). I don't think I had any other codes at the time though. Just a thought.
 

BendRover123

Full Access Member
Joined
Mar 29, 2020
Posts
79
Reaction score
17
Location
USA
Landrover 2008 LR3 V8 the engine light is on for me an with bank 2 catalyst is depleted message. I imagine there is a lot of R/R to remove heat shields and anything in the way to reach the manifold exhaust bolts, or whatever holds the cat flange in place. Also you would want to install a set of new bolts to prevent them from cracking afterwards due to thermal cycling. Also if one converter is depleted you probably want to replace both at the same time. Just like light bulbs. You can buy them for ~800$, maybe find a muffler shop to do the work, I imagine that wouldn't be $3200 total.
 

Members online

Forum statistics

Threads
36,255
Posts
217,952
Members
30,493
Latest member
A562NV
Top