I'm in the process of improving the drive ability of my 3.0 TD6 FF

So far in the last few k I've done the following:
Gearbox oil + filter
Good Service including Air Filter new PCV
Eco Tuned Gearbox
EGR bypass

Next on the list is a custom remap on a 4x4 rolling road. I'm toying with the idea of de-cating before the remap. I'm no stranger to remaps so i know that all engine mods should be done prior to the map, however i cant find much info on whether the decat is actually a worth while mod. If it isnt going to make a noticeable difference to mpg/bhp/drive ability then i'll leave it alone. I've also heard that it can increase the noise inside the cabin?

Not done it myself, but I understand the exhaust note is noisier and it smells more like a diesel if you are stood near the rear with it running.

As to mpg and performance, I'm sure someone will have the answer........ I think ebajema may have done it ? 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

I was thinkn of doing the same so be intresting to read replies.
Found a supplier on flea bay aboot the £100 mark Made in Scotland frae 'Girders'

Smell wouldn't bother me too much. Don't really want any extra noise, td6 isn't a particularly pleasing engine to listen to.

If the majority of people say it improves throttle response, mpg, bhp or and other worth while things I might consider it prior to the map.

It was the £100 ones I saw on eBay to.

"Don't really want any extra noise, td6 isn't a particularly pleasing engine to listen to."

Maybe I was lucky, but I found my TD6 smooth and quiet.... Previously..
Vogue SE TD6
Defender 90 2.4
Defender 110 TD5
Vogue 3.5 EFI

Not me, I have a petrol SC and the cats are still firmly in place and seem to be working. Don't feel the need to take them out (yet) as 400 odd horses is enough for me (at the moment at least ). MY 2010 5.0 SC Galway green and sand interior!!
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!

I find it quite an unrefined sound. Hard to describe really, its all personal preference I suppose, but, to me, it doesn't have a lot of character. To me its only noticeable sub 40mph, I find it louder than I would like.

TD6 sound is a bit "Agricultural" no idea why its so different to BMW's with same engine other than different tuning and BMW laughing....

The noise is more from the tune. BMW's are meant to pickup and go quicker and also the butterfly valves help as well.

Lr wanted as much torque as possible from the engine from the offset for easier work off road, and the td6 has a fair amount of noise from its injectors and their injection cycle which is adjusted more for torque again, rather than super quick pickup.

The decat will help bring the turbo spool up down the rev range and help with pickup as the turbo is able to breath more easily.

Another mod worth doing could be going over the inlet tract and removing some 90' bends for some more gentle 45' bends where possible as that will help with spool up and torque.

The freer the flow of air the better as it will help reduce inlet temps and work the small ic has to do and give your a cleaner burn as the ic isn't that big for the size of the engine and doesn't get the best airflow over it. This will help come remap time as while the turbo can only go upto a set psi before performance degrades massively, keeping the inlet temp down and the path freer will help reap more torque from it. FFRR MY06 facelift With TDV8 Alloys Zeros/ATR's
Mantec Sump Guard, Rigid Load liner, MY10 BT upgrade.

i could be wrong, but my understanding of the new mot,s is that if it had a cat fitted as standard new, it must be on for mot or its a fail
cheers hammie 2003 ffrr v8 vogue

Sorry ebajema, its the chap thats in "The Other Eastbourne" when I come to think of it. Username is on the tip of my tongue..........

 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

Oh don't do it!!! They STINK without a cat! one of my younger customers had his removed and my god it stinks like an old ice cream van... And no noticable gain either...

The mot only involves a check for the dpf/cat, not its function or internals on Diesel engines.


If the guts are knocked out or a new straight they silencer put in its place they won't know

Ideally a pipe would run thru the box full of little holes and then fibres put around that and the box then sealed up so it was in effect straight thru but the noise would be taken out of it, damped I think it's called. FFRR MY06 facelift With TDV8 Alloys Zeros/ATR's
Mantec Sump Guard, Rigid Load liner, MY10 BT upgrade.

My lad has de chatted his disco and it stinks like an old tug boat and is much louder. He swears it has a lot more poke but I can't feel it! After his re-map there was a significant improvement but I'm not convinced any of it was down to the de-cat.
He has not had any mot problems or even questions!

I've heard of people doing it on petrol cars (not RR) and noticed a big improvement in power.

The mot check for a cat being in place only applies to "spark ignition" engines not " compression ignition" engines ie diesels.
If you wish to remove it you can but as CTC says the exhaust stinks, had a Disco with no cat and it was awful.