2008 LR3 with codes: P0441 & p0420

philwas2

Member
Jun 11, 2013
10
0
florida
MY CEL light comes on for a bit, then goes off. I am getting these codes on my truck:

Po441 says: evaporative emission system incorrect purge flow
P0420 says: Catalyst system efficiency below threshold bank 1

They seem to clear themselves after a few days, then they return in a month or so. Does anybody have guidance as to where to begin looking to remedy this? I've got 140K mikes on her & I DO NOT wish to replace the cats on this $$$. Besides, I am not sure the codes would clear themselves if the cats were truly bad.

Thanks in advance for your helpful input!
 

ERover82

Well-known member
Nov 26, 2011
3,899
450
Darien Gap
I've got the P0420 as well, but live in an area without emissions testing so I don't care. It's present most the time but occasionally disappears. I'm guessing the cat is just marginally inefficient.
 

Colin hughes

Well-known member
May 4, 2004
265
2
Cannington, Ontario
I get codes for both banks on a regular basis. I did replace one cat with an aftermarket unit last summer but still get the CEL. Like you, it stays on for a few cycles and goes off. Seems more in winter than summer. I put it down to the fact LR engines run a bit rich and ethanol/winter gas. I, unfortunately, live where we need emissions test every two years so I just make sure to get the test done when the light is off as our tests do not involve tailpipe emissions, just computer scans.
 

philwas2

Member
Jun 11, 2013
10
0
florida
I get codes for both banks on a regular basis. I did replace one cat with an aftermarket unit last summer but still get the CEL. Like you, it stays on for a few cycles and goes off. Seems more in winter than summer. I put it down to the fact LR engines run a bit rich and ethanol/winter gas. I, unfortunately, live where we need emissions test every two years so I just make sure to get the test done when the light is off as our tests do not involve tailpipe emissions, just computer scans.


CH
That's exactly why I am reluctant to replace the cats. Something (my wallet) makes me want to believe there is more to this. I know nothing is as it once was, but cats USED to last for quite a long time!
 

Tyrone

Member
Oct 14, 2015
6
0
Atlanta, GA
I'm in the process of changing out the cats and O2 sensors in my 06 LR3 as well. I've been getting an intermittent 420 but regular and less regular 171 and others after having had two bad coils. My MPG also dropped to 9.5. I have to do emissions in the next two weeks and unfortunately I can't get to IM Readiness before the CEL comes back on. Getting to the cats is a lot of work. Interestingly enough after resetting the ECU my MPG jumps up to 13.5 but drops again when the light comes back on. I hope replacing them and the O2 sensors takes care of the problem.
 

Shoggin

New member
Dec 31, 2016
1
0
NH
Hey guys, question for you as a newer 2007 LR3 owner myself;

For those with these codes; What are you running for fuel, reg or prem?
Also, have you done a proper injector cleaning in a while? (Through the fuel rail) or intake cleaning (through the vacuum lines)? (Not just pouring additives into the fuel tank that is.

Best Regards,
Shaughn
 

discostew

Well-known member
Sep 14, 2010
7,706
1,015
Northern Illinois
CH
That's exactly why I am reluctant to replace the cats. Something (my wallet) makes me want to believe there is more to this. I know nothing is as it once was, but cats USED to last for quite a long time!

Unfortunately it's almost a sure thing that it needs a cat. The cat code can only get stored if all your o2 sensors have passed all the readiness tests. But I suppose a shitty aftermarket cat will also test bad. One thing you need to know to avoid wasting money is the fact that bank one is the right side on your truck.

Your evaps code will more than likely be your DMTL pump. It's mounted to the charcoal canister.
 

BDKR

Member
Mar 21, 2017
14
0
North Carolina
I would definitely address the evap issue first. Clear codes then see if the code for the cat comes back.

@Shoggin. I normally do a top end clean with Seafoam on my cars. Haven't yet on the LR3 but the old lady is usually in it. I think I'll have a shot this weekend.

I forgot this from earlier....

https://www.youtube.com/watch?v=Dfj-F_pTj5M

This vid is pretty silly but it helped me with evap issues on my 850R and 323i.
 
Last edited:

stu454

Well-known member
Dec 15, 2004
5,407
61
Atlanta, GA
Hey guys, question for you as a newer 2007 LR3 owner myself;

For those with these codes; What are you running for fuel, reg or prem?
Also, have you done a proper injector cleaning in a while? (Through the fuel rail) or intake cleaning (through the vacuum lines)? (Not just pouring additives into the fuel tank that is.

Best Regards,
Shaughn

Premium (91-93) only. Mine has that listed on a sticker on the inside of the fuel door.
 

BDKR

Member
Mar 21, 2017
14
0
North Carolina
That would be very rare.

I tend to agree actually, but be thorough. If P0441 is indicative of a small leak, why not start by checking the easiest thing to check?

That said, not implying I know better. Just been down this road a couple of times myself :)banghead:) and speaking from personal experience.
 

discostew

Well-known member
Sep 14, 2010
7,706
1,015
Northern Illinois
Wouldn't he get a DMTL related code?

And since P0441 indicates small leak, then logically the system must have been able to pressurize to determine this.

That's what the P0441 is all about. The pump is such a common failure that it's safe enough to replace it right out of the gate. Then run the test again and worry about the evap lines and purge valve or all the other happy horseshit that can cause a small leak fault.

I've seen them leak smoke out the electrical connector area enough times that I put grease in there to seal it better. If you do a real leak test you need to close off the vent valve portion of the valve with a jumper wire then run the smoke test. The other way is to plug off the port that actually vents by taking the rubber hose off it and capping it with a plug. Problem is that's the valve that causes the most problems in my experience,so I like to test it during my smoke test.

The way the system tests for a small leak is by running the pump until a set amperage draw is going thru it. As the system pressure builds the amperage goes up. If the system has a leak then the pump will never reach that amperage because it can't overcome the loss of pressure thru the small leak.

And if anybody started al this testing without looking at the fuel filler cap and seals then that person is an idiot. Of course I would look at that, but I wouldn't test that theory with a new fuel cap.
 

BDKR

Member
Mar 21, 2017
14
0
North Carolina
Ahhh..... I see your reasoning. :D

Those pumps wouldn't happen to be the same made for BMW would they?

That's what the P0441 is all about. The pump is such a common failure that it's safe enough to replace it right out of the gate. Then run the test again and worry about the evap lines and purge valve or all the other happy horseshit that can cause a small leak fault.

I've seen them leak smoke out the electrical connector area enough times that I put grease in there to seal it better. If you do a real leak test you need to close off the vent valve portion of the valve with a jumper wire then run the smoke test. The other way is to plug off the port that actually vents by taking the rubber hose off it and capping it with a plug. Problem is that's the valve that causes the most problems in my experience,so I like to test it during my smoke test.

The way the system tests for a small leak is by running the pump until a set amperage draw is going thru it. As the system pressure builds the amperage goes up. If the system has a leak then the pump will never reach that amperage because it can't overcome the loss of pressure thru the small leak.

And if anybody started al this testing without looking at the fuel filler cap and seals then that person is an idiot. Of course I would look at that, but I wouldn't test that theory with a new fuel cap.
 

jymmiejamz

Well-known member
Dec 5, 2004
6,008
361
35
Los Angeles, Ca
Those pumps wouldn't happen to be the same made for BMW would they?

Yes they are, and Maserati. I'm sure other brands use them as well. The lead training instructor for Maserati worked on the engineering support team for Bosch on those pumps, IIRC.