Hello
I have had my '02 Disco in and out of the shop for two weeks as my mechanic has been struggling with O2 sensors. All of the sensors have been replaced and the "service engine soon" light is still on as the truck keeps throwing the code for front bank, left O2 sensor. The mechanic seems to think that the wiring coming from the sensor is grounding out some where on the truck. All the terminals and connections have been cleaned and tightened up so he feels that this is the only possible issue left, save a "computer problem.". I have had a hard time getting upset with him as every time I leave the shop and drive less than 3 miles home, the light returns, but he offers to "run down the problem" for free. So, my question to all of you is, does this make sense? Are the issues I'm experiencing congruent with what the mechanic is telling me? The truck seems to be running fine otherwise. Your help, as always, is appreciated.
Cheers,
Gabe

 

95% of all O2 codes on a Land Rover are because the engine needs a tune up, that means new spark plugs and spark plug wires.
HOWEVER you cannot use cheap plug wires, if you do the codes will come back.
Land Rover Parts & Rover Accessories From Atlantic British | Discovery, Range Rover, LR3, LR2, Defender, Freelander and Land Rover Series Parts & Accessories has tune up kits, everything you need for a good tune up and they will ship directly to your shop.
Or you can order the parts cheaper else wear, but use only Magnecor, Kingsbourne or STI plug wires.
Spark plug buy whatever you want, they are all the same, I use $.99 spark plugs.

 

Spike
Thanks for the response. The plugs and wire were done when I first got the truck, 1 month ago, as part of a tune up I had done along with valve cover gaskets and an oil change. So if those are in good working order would the O2 thing make sense?
Gabe

 

And the code number is? Many codes take two drive cycles to show up, so he works, clears them, cranks truck, they're gone, you drive , second drive cycle since reset, they pop back.

 

Gabe, we have to have the fault code numbers to know what is wrong.

 

There are many O2 fault codes, we need to know the codes so we know the exact fault.
System to rich usually means bad tune up, non responsive means bad O2.

 

Hello all,
I am happy to report that the "Service Engine Soon" light is off! The wiring going from the O2 sensor was grounding out on the tunnel. My trusty mechanic (who did all the hunting for FREE) had to hunt this down and patch the wire but she's running great! I have completed my first oil change with Rotella Synthetic and my Disco is running the best it has since we got it 6 weeks ago. We are loving the truck, taking the dogs to the beach tomorrow with all the windows down and both sunroofs open!
Cheers,
Gabe