The "cat"[ td5 exhaust.]

[bob10]

Could someone please explain to me ... the cat... relating to the exhaust system. I assume it is short for " catalytic converter", whatever that means. From what I have read, I assume it is a good idea performance wise, to replace it with ... something?....Be kind to me, Iam a distant relation of Sgt. Shultz [ I know nothing!!] Bob

[Panya]

No cat in td5 exhaust system...

[Pedro_The_Swift]

Sorry Bob,, catalytic converter's are a V8-ULP thing,, put in to clean up the exhaust fumes,,
all they do is slow down gas flow I reckon,,,:wasntme:

[Tombie]

Some TD5 had cats

My unofficial :) recommendation:

Get rid of it

[rangieman]

Some TD5 had cats

My unofficial :) recommendation:

Get rid of it
True some Td5,s did have cats but you will be hard pressed to find a exhaust place that will remove it for legal reasons and the fine they could get .

Best to go to the wreckers and get a second hand engine pipe minus the cat or remove your engine pipe and have a exhaust place fab a new pipe minus the cat and then fit it your self ;) While your at it remove the centre muffler :angel:

[Blknight.aus]

The Cat is the catalytic converter top points for that. What it does for you is converts nasty gasses from the engine into not nasty gassed for the environment. it also produces water as a part of the deal. (which is the white smoke you can see coming out of some cars on a cold enough morning.

Some TD5's had them some had a diesel particulate filter, both to the untrained eye look about the same. the big question is do you need them? Yes, you do, they were factory fitted and so must remain fitted, just like the EGR just like a couple of other things that are done for emission reasons. Can you get away without them? Yes, without the cat or the diesel particualte filter up to about 2004/05 (and only because I havent tested against the new standard) the td5 passes the Australian emission standards for Diesel engine without any of the goodies that are down stream of the turbo.

do they make a difference in performance? well that depends. If you only change or remove the cat or the DPF then you wont get an increase in performance. IF however your cat/DPF was clogged and you remove it then yes you would notice an increase in performance but it would only be up to the vehicles original performance standards.

If however you had added something akin to one of Tombies Proton energy pills then yes removing the DPF/CAT makes a difference, swapping out the exhaust in total for a 3 inch mandrel bent unit makes even more difference.

But, I hear your hippy greenpeace advocates voice saying, Can you have the best of both worlds full TPEP performance with a butteryfly farting exhaust? again Yes, But it costs and In my opinion the cost is worth it just to avoid the hassle of having to prove that yes the 2003 td5, commodore lunching, traffic light drag launch Defender is in fact totally legal without the gear in the exhaust system.

Lets face it design it and use it right, the exhaust system (with the exception of the gaskets and mounts that you trash taking it apart to get to bits of the vehicle) should last you 10 years.

[Panya]

Yet another day where I learn something new. TD5 EU2 - no cat, EU3 - cat... Funnily enough my car had EU3 spec EGR gubbins and yet EU2 for the exhaust. 2002 model so I guess was at the changeover... and no CDL:mad:

[bob10]

Blknight, thank you for the explanation. Since joining this forum, I have learned so much from members , I have had to take up drinking Tasmanian beer [ cascade] in order to grow a second head to keep it all in. :D Bob

[Redback]

Blknight, thank you for the explanation. Since joining this forum, I have learned so much from members , I have had to take up drinking Tasmanian beer [ cascade] in order to grow a second head to keep it all in. :D Bob

Better a second head, than losing taste buds drinking that QLD rubbish;)

Baz.

[Hamish71]

There is another option (s).
There are such things as "hi-flow cats".

You can get the stock one removed, and replace it with a higher flow cat. this will, in theory, increae performance. However as Blknght stated, not really worth it unless you have "tuned" your engine.

It is possible to get an exhaust place to remove a cat. Simply tell them that you use your car in competitions, off road, on private property. Instruct them to make an "insert" for your exhaust. ie. cut either side of the cat, put 4 flanges in. That way you can unbolt the cat, and insert a straight pipe for "competition purposes". I myself have gone a mandrel bend 2.75 in system, with a high flow cat...which sits on my shelf "during competitions".

[Rosco]

Better a second head, than losing taste buds drinking that QLD rubbish;)

Baz.

Oihhh ... careful there cobber. It hasn't affected me too much :woot::woot:
:p:D

[Blknight.aus]

Blknight, thank you for the explanation. Since joining this forum, I have learned so much from members , I have had to take up drinking Tasmanian beer [ cascade] in order to grow a second head to keep it all in. :D Bob

Since your semi local, you're welcome to invite yourself round to my place on any of the weekends that Im spannering on something thats related to something you want to know about.

If theres something else specific you want to know about and the site search doesnt bring up the info and youve checked the good oil just do what you've done here and pop a question into the tech forum.

Theres a few of us who troll it on a regular basis so help wont be far off.

Like I keep telling people I meet on the side of the road, AULRO its what LRA should be.

[Benny_IIA]

Since upgrading to a eu3 td5 I will getting one of these from frozen boost
https://www.aulro.com/afvb/images/imported/2011/03/1068.jpg
This is not a catalytic converter!
This is a special section of straight pipe with a housing that looks exactly like a catalytic converter



High Flow Cat (http://www.frozenboost.com/product_info.php?cPath=210&products_id=573&osCsid=3ea30a1ac744f0ce186d37ec6a1229b9)

[scott oz]

I purchased a standard LR replacement pipe and it had no cat converter? why not Just do that:angel: