Decided to remove the internals of the CAT on my 1999 L series... results are amazing !
The performance is vastly improved low down, a world of difference.
My FL has 210K Km on the clock so the Cat could well have been slightly congested over a normal lower mileage model, however the FL drove fine before.
Difference now though is much more torque low down, turbo kicks in much sooner - basically a different vehicle. Pulls smoothly and progressively at low revs.
The only mod I have done that made a really noticeable difference. Removing EGR was slightly beneficial but knocking the innards out of the CAT made a night and day difference.
Highly recommended mod. Absolutely no need at all for a special pipe or fitting, just remove the cat and smash the innards out with a piece of tube or bar..
Really put a smile on my face and the best value for money ever. It really is like driving a different vehicle !.

How much difference the high mileage makes in relation to cat added back pressure is unknown but ANY back pressure on a normally aspirated or turbo charged Diesel is detrimental to performance.

Thoroughly, utterly and entirely recommended. !


Joe

The cat is wider than the rest of the exhaust, suggesting compensation for the increased resistance to flow, although there must be some turbulence in the mesh. At your mileage I suspect there was some clogging, if you can feel a difference in the power delivery. I just hope it still passes the emissions test (it probably will).

Anyway - nice one! Remember the mesh you've removed might be valuable so don't throw it away.

guineafowl21 said:

The cat is wider than the rest of the exhaust, suggesting compensation for the increased resistance to flow, although there must be some turbulence in the mesh. At your mileage I suspect there was some clogging, if you can feel a difference in the power delivery. I just hope it still passes the emissions test (it probably will).

Anyway - nice one! Remember the mesh you've removed might be valuable so don't throw it away.

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Hi Guineafowl21, All the MOT (IPO in Portugal) tests on an 'oiler' (Diesel) are basically rev it and look for clouds of Cr&p..... so no worries there. They are more concerned re oil burning high mileage engines (Usually dense blue smoke) and heavily over-fuelled engines (Black sooty smoke).
No direct 'emissions' tests are done.
All CATS must introduce a certain amount of back pressure and hence reduce diesel engine performance (Petrol engines benefit from appropriate back pressure), and definitely, yes, I agree that on a higher mileage unit the cat is more likely to be suffering from contamination and poisoning causing increase in back pressure and reduction in performance - a very noticeable one.
About 10 years ago my bride filled her Citroen AX Diesel with Petrol... .... car ground to a halt - I had to go out and drain the fuel completely, refill with diesel and bleed it of petrol and air.. all went well... about a month or two after, the car lost power on hills and this steadily got worse and worse. After checking all obvious things it came down to the cat - removed it to test and all was perfect again. The neat petrol passed to the cat had severely damaged it causing a 50% blockage of the unit due to contamination. I think all cat equipped diesels probably do gradually lose performance as mileage increases specifically because of the contamination of the cat - (IMHO)
And, as said, even in a new vehicle, the cat is detrimental to performance but has a positive effect on emissions (as far as the regulations go)
On vehicles equipped with Lambda sensors I would definitely not recommend any removal though !
The ubiquitous L series though - what a superb and reliable unit without all the modern added junk lol

ps - all the knocked out mesh was 'disposed' of in the waste bin - naughty - but........
(tum te tum te tum )
Joe

I meant the mesh contains certain precious metals so sell it to a scrapyard rather than bin it...

guineafowl21 said:

I meant the mesh contains certain precious metals so sell it to a scrapyard rather than bin it...

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Lol, yes, I am aware of that, however, I know of nowhere that they could be sold in mixed powder form.
A complete new unit is only around 100 quid so I doubt there is actually any practical value. I can imagine a breakers yard collecting them and selling them for X amount per ton but in a single form..... difficult.

To be honest, it reminded me more of remains from a crematorium....
I should have put them in a jar and sat them on the mantelpiece.... -

it is platinum that's in the cat but not a lot .

When I decatted my Defender I got £35 for it from the local scrappie. Because the replacement pipe only cost £25 I was effectively paid £10 for doing the job! Little things like that please me...

Wow, that's a good price !. I didn't want to remove the cat casing though but hey- bargain !..

Hmmmm. I wonder what they would give me for 'Tiddles'

how do you remove the internals ?

Hi Bluemax, just use a piece of pipe / tubing or a long extension for a socket set - smack it with a knocking stick or Irish screwdriver . The inner part is a fairly brittle ceramic type material.
Looks something like this - it breaks up with a bit of welly and falls out the other end - you can start smashing from both ends no worries.



Joe

Here is a youtube vid of the process on a different cat - principle is exactly the same - the fl was easier to do though.