Thread: Discovery TD5 catalyst ...

IIRC - if the vehicle is fitted with a cat converter, then it needs to be retained.

That said, a number of people, have "altered" thier exhaust with a straight thru pipe. The difference is noticable straight away, with more power on tap.

If you click on the search button on the top right, and look for TD5 Exhaust, or Centre Muffler, you will find a number of posts on the subject.

Oh, and BTW - welcome to the fold.

Legally speaking your vehicle was fitted with a cat and therefore it must be fitted.

in reality the td5, unless youve gone stupid with it meets the required emission control standards without it (up to 2005 at least which was the last td5 I had emission checks done on post mods)

now heres the kicker...

The last one I checked was a defender and as its classed as a commercial vehicle (so sayeth LRA which is why you cant get the extended warranty for it) and they have a slightly different set of rulings than private vehicles.

do with this information as you will.

Hi White Pointer,

What type of flex joint does your down-pipe have, wire or a bellows? The bellows type on later D2s stretch and rattle against their internal stop. To test, the pipe below the joint can be lifted by hand to stop a light rattle at idle if the bellows has stretched. Just a possible alternative to the cat rattle.

You can go to the extent of opening the cat, removing the catalyst then sealing back up, but its easier to just replace the pipe with a decat version. Doesnt take long to change out, however its a lot easier if you have a hoist or work pit. I did mine in the truck workshop and it took me 30 minutes. For that "original" look, get an exhaust shop to cut the cat out and add an identical looking resonator in the same place as the original cat.

Flange bolts on the turbo can be a bit tight so CRC the hell out of them first and leave for 10 or 15 minutes. One is a bit hard to get to but with about 2ft of extensions you can get 2 of them from underneath quite easily.

The rattle may also be the heatshield above the main muffler. Its a foil covered pressed fibre unit that will deteriorate where the bolts hold it. Fixed mine by adding big galv washers each side and then the original bolts and washers to spread the load on the shield when re tightened.

Cheers

Andrew

Take it out
I know that technically speaking it was fitted and should be retained, however, according to advice given from an LR dealer, it is not an Aust.requirement and wont cause an issue for rego. You will find after removal it will be a bit better on fuel and performance as the the failing units cause some significant restrictions.

cheers

Originally Posted by Basil135

IIRC - if the vehicle is fitted with a cat converter, then it needs to be retained.

That said, a number of people, have "altered" thier exhaust with a straight thru pipe. The difference is noticable straight away, with more power on tap.

If you click on the search button on the top right, and look for TD5 Exhaust, or Centre Muffler, you will find a number of posts on the subject.

Oh, and BTW - welcome to the fold.

G'day,

That's what I thought. I don't mind making my contribution to making everyone's air better to breath. I've contacted a mob called Microfresh Filters to see if they can make a replacement. They reckon their's don't have a huge back-pressure affect. Anyone used them?

Thanks for the welcome.

Regards,

White Pointer

Originally Posted by Blknight.aus

Legally speaking your vehicle was fitted with a cat and therefore it must be fitted.

in reality the td5, unless youve gone stupid with it meets the required emission control standards without it (up to 2005 at least which was the last td5 I had emission checks done on post mods)

now heres the kicker...

The last one I checked was a defender and as its classed as a commercial vehicle (so sayeth LRA which is why you cant get the extended warranty for it) and they have a slightly different set of rulings than private vehicles.

do with this information as you will.

G'day,

Thanks for that. It was a toss up whether to buy a Defender 110 Xtreme or the Discovery back in 2002. I still wonder if I made the right decision.

Regards,

White Pointer

Originally Posted by Graeme

Hi White Pointer,

What type of flex joint does your down-pipe have, wire or a bellows? The bellows type on later D2s stretch and rattle against their internal stop. To test, the pipe below the joint can be lifted by hand to stop a light rattle at idle if the bellows has stretched. Just a possible alternative to the cat rattle.

G'day,

The down-pipe is the bellows type.

I spent some time under the car and in the engine bay trying to find a cause and was convinced it was the catalyst because of the loss of power at 2,200rpm through to around 2,700rpm and the horrendous noise that sounds like a concrete mixer with nothing but 3/4 gravel in it in this range. Below 2,200rpm its smooth and quiet. Above 2,700rpm it quietens down and gets a huge power boost - therefore I'm convinced it's obstructing gas flow in the most usable rev range.

MR Automotive in Redcliffe confirmed my suspicions that the cat was stuffed a few weeks ago.

Regards,

White Pointer