I'm the original owner of a 2001 Land Rover Discovery, 200K miles. I've modded the vehicle for Overlanding, really enjoy it, and really want to keep it running and operational as long as possible. However, I've been having issues getting emissions problems correctly diagnosed. At this time, the CEL is on and at least 2-3 faults are the cause - per the California SMOG shop, the Air Pump fault and both CATs have the Efficiency Faults come up. There maybe one other fault, but probably not related - ABS fault. After a lengthy monitoring cycle, I was finally able to trigger the faults by following the Drive Cycle I found here on another thread - much appreciated!!

The issue I'm having is neither the SMOG shop nor my local shop wants to spend the time to figure out the causes on why the faults are occurring. Apparently the diagnoses can be difficult and nobody wants to just start replacing parts unless they know the cause for the faults.

At this time, I'm planning on going to the dealer (Land Rover San Diego) for a thorough diagnosis.

With that:

1. Does anyone have any thoughts, recommendations on how to resolve the Emissions issues? What could be the cause?
2. Are the dealers capable and competent to diagnose the root cause for the emissions issue without resorting to just replacing parts?

Thanks!

 

Diagnoses should be relatively simple if you get a code reader that can correctly interpret the Land Rover codes. You won't be able to get a good handle on the best approach to take until you have a better idea of the specific components that are causing the problems.
ABS faults will sometimes light the Check Engine Light. Even if your emissions issues are all clear, a lit CEL for any reason will fail your inspection.

 

Unless your Land Rover dealer happens to have a mechanic who understands these older LR’s they won’t have a clue about your Disco. Usually you are best on your own, or if you can find a mechanic who understands and likes these vehicles. In North America they aren’t easy to find.

 

Yep, that's the problem I'm concerned with - finding someone who knows how to correctly assess it. The LR dealer near me is very large and they do have 3-4 Disco II's on-prem waiting service, so maybe they have a tech or 2 that knows something about these. I'll drop it off there and see what they come up with.

 

Like said O2/emissions issues are pretty easy to diagnose most of the time. Unlike what was said it's not voodoo that some magical mechanic needs to know all the ins and outs of. All "modern" gasoline cars use an Oxygen(Air Fuel Ratio) sensor system for emissions.

The short of it is any mechanic will need to run a diagnostic which will give them numbers that will guide them towards what the issue is. Catalytic inefficacy codes do not Ultimately mean that your cats are bad and need replaced, they are merely the computers way of saying hey there is a problem with the Air/Fuel/Exhaust that I cannot make corrections for.

I went around chasing my tail with an intermittent issue of a ground in the ECU failing on mine. I can give some input if you can post up some numbers. A cheap way to read codes and get some numbers to share is the Torque App (Android $5, maybe Apple idk?) and a bluetooth(Definitely Android, last I knew Apple needed to use a wifi adapter) OBD2 reader.

Sample data, might not be from my Disco