Originally Posted by Savannah Buzz
Welcome. What code turns on yonder light? Parts stores will usually read for free.

I had the CEL code read by Advance Auto. The code turning on my CEL is P0430--Catalytic Converter . The rep from Advance Auto said that the message given was "threshold too lean". Usually lean is a good thing, but I'm thinkin' not so much of a good thing in this case!

I'm pretty much just learning from this Forum, so I can't yet do alot of repairs myself on my D1. But, I'd appreciate any thoughts on what Code P0430 means, what kind of trouble I'm in (or headed for), and how fast I'll need to take it to the nearest d(st)ealer or latest indy mechanic, who'll tell me with a big smile that he works on anything, except Land Rovers and SAABs, and, boy, do I sure know how to pick cars .

I travel through 3 states, but this vehicle is inspected in NJ State. My inspection is valid until Oct 2014. So, if emissions is the issue triggering code P0430, I'm ok until then...I think?

Please let me know your thoughts. Any advice is appreciated. Thanks in advance!

 

Attached please find Rover manual for the GEMS ECU, and start on page 8. The system monitors the cats for function, and it belives one of yours it not functioning. Certainly could be an O2 sensor

 

Thanks, S. Buzz. I really appreciate now having the ability to understand what my trouble codes mean, even if I don't know how to fix them yet .

I downloaded the GEMS Diagnostics manual and am reading pgs 7-12 abt how the catalyst can be throwing my trouble code. Stage 2 would only be invoked if my catalyst also failed Stage 1. To determine if catalyst performance has fallen below required level, a value "Cat Norm Area Difference" is calculated, which is measured in Volt secs taken from 2 oxygen (O2) sensors, before & after the catalyst. So, as you said above, it could definitely be a faulty O2 sensor.

In addition to O2 sensor, the "Catalyst Monitoring Operation" chart on pg 12 also states "ECT" in the Secondary Parameter column. So, I was thinking it could be a faulty ECT sensor, used to detect the temperature of engine coolant circulating within the engine. If ECT sensor is faulty, it'd transmit no/bad ECT signal to the engine ECU. Maybe?

And, I don't fully understand catalytic converters, so I'm not sure, if my cat's faulty, can a part, like only the filter, be replaced ? Or, due to emissions standards, is the LR cat a fully sealed unit that needs to be completely replaced with a new or rebuilt one ? That'd be expensive!

Let me know if any suggestions. I'll do my own research, too, and then decide if it's time for a trip to a tech.

 

Brief update:

I'm getting trouble code P0430 Catalytic Converter, "threshold too lean", and a possible source per this Forum could be O2 sensors. As a first step, I checked my service records, and I had the O2 sensors replaced 4 yrs ago, in Aug 2009. I'm wondering if that could be the problem again.

Can someone give me an idea of how long the O2 sensors (installed in 2009) should last under normal driving conditions. Should they be replaced again ?

The Catalytic Converter repair was done at a LR dealership in Aug 2009.

The parts invoiced/installed are listed below, but I don't know if it's likely that these parts failed again. It is 4 years later, though. The CEL stayed off for abt 3 yrs; it's been on for abt 1 yr now (since July 2012).

Date: Aug 2009
Problem: CEL on
Solution: Tested and replaced INT broken CAT Convertor Assembly, along with INT shorted O2 sensors. Retested and road tested. OK at this time.
1 WCD104650 3166E -- Exhaust
4 AMR6244 Sensor -- HEGO
2 ETC4524 Gasket
6 WYH5000060 Nut

An indy mechanic thought that the problem might be related to a faulty ECT (engine coolant temperature) sensor. He said that, if my ECT sensor was faulty, it's possible that not enough fuel is being pumped to the engine, and that can be causing the CEL to illuminate. The GEMS manual mentions ECT on pg 12, so it seems that could be a source of my problem. I only discussed the problem with the indy mechanic; he hasn't worked on my Dscvry yet b/c I want to understand the possible problems throwing trouble code P0430, before I have the Dscvry serviced.

If the parts ain't broke, I don't want to fix them again !

Any help is appreciated. Thanks!

 

So you had 1 cat and o2 done in 09?
Maybe the other side is bad now
02 sensors and cats should last longer then 4 years but ymmv
You can fool the down streams to stop the code use spark plug anti foulers to extend the bung so they no longer protrude into the pipe

 

Thanks, Tom. Not to sound stupid, but I didn't know there was another side to go bad. Sorry . I'm trying to learn this stuff myself b/c not much that I'm told by experts about my Dscvry ever seems to make much sense. But, I do admit that I still have alot to learn mechanically. I'll have a mechanic check if both sides of the Cat were repaired or only one side. I'll also suggest using spark plug anti-foulers to remove the CEL, if all else looks ok.

I understand your point that, for a given repair, my mileage may vary. My mileage when the CEL first appeared in Aug 2009 was 158,134. After that dealer repair, I drove 3 yrs with no CEL and up to mileage of 185,657, when the CEL illuminated again in July 2012. I took my Dscvry back to the same LR dealer as in 2009 to see if they could fix the problem again.

Dealer diagnosis (July 2012):
"Check engine light is on for faulty O2 sensors and cat converter. Engine oil leaks are dripping onto sensors and hot exhaust system. Vehicle should not be driven, and it is not cost effective to repair." I didn't listen to them.

Dealer told me they'd give me $500 for my Dscvry. I told them the new tires on it and the full tank of gas in it were worth more than $500. I said not to touch it, and I sent a flatbed to get my truck .

In Aug 2012, an indy mechanic found trouble code P1316 engine misfire. He replaced spark plugs, spark plug wires, and gave Dscvry a basic tune-up. Code P1316 went away, but CEL stayed on. He said that I had a flat cam load, but I'm not sure if that is contributing to code P0430 . He couldn't get the CEL to stay off; it kept coming back on.

Dscvry seems to drive fine, and I'm up to mileage of 191,675. But the CEL is still illuminated. So, I figured I'd raise the issue on this Forum to see if I should be worried that the Dscvry would catch fire if I turn the key in its ignition (as the dealer told me) or just keep driving it until it dies (as the indy mechanic told me). I'd really like to get the CEL to stay off !

I guess you can now understand why I am a little confused .

 

You can "see" the ECT value on a scanner, it will start out at ambient temp and rises to whatever the engine is producing. Mine runs around 185 on back roads and is hitting 201 -205 in traffic. If you unplug it the reading will go to -40F.

 

I don't own a scanner yet, so I can't do it myself. Is reading the ECT on a scanner something that a parts store, like Advanced Auto, can do for free? Or should I only trust a mechanic to do it?

 

I installed my Ultra-Gauge tonight. I didn't get to set-up all the gauges, but, immediately, the Alarm started sounding (I'd expect nothing less for me ) reporting a Trouble Code:
Cat Bank 1 Sensor 1
Value 8789
Alarm Max 2011

I'll read more of the manual tomorrow to see what that trouble code means, and I haven't bought a thermostat yet, but if you (or anyone) can point me in right direction re: trouble code, it will save me some start-up time. Thanks!

 

Ok, Tom, it seems you are correct.

Driver's side cat is good; if bad, it'd throw trouble code P0420, which I'm not getting. Driver's side cat looks like a universal part. It was cut and welded in, but a very good welding job was done, and it's fine.

But...passenger's side cat is bad now; that's what's causing trouble code P0430. That cat looks original, like it's never been touched. I asked a mechanic, and he said that I'll need to replace both cats (driver & passenger) to repair passenger's side b/c the new part comes with both cats mounted on a Y-pipe set-up, unless I find a shop that'll cut & weld the part for me (but, he doesn't weld). That doesn't make alot of sense to me b/c it was a LR dealer who performed the driver's side cat repair for me in 2009, so I'd think that, if the dealer could cut & weld the new part to install the cat on only 1 side, an indy shop can, too. Idk. Funny thing is that for the price that I paid for the cat repair at the LR dealer in 2009, it looks like I should've gotten 2 new cats, not just 1 .

If anyone has experience regarding replacement of only 1 cat (passenger side) and/or where to get the cat repair done, please share your suggestions. Thx !