300Tdi Exhaust

Does anyone know if the front downpipe with "cat" can be straight swapped for a "non cat" downpipe as there is an awful big difference in price and I can live without a "cat"!?

Cheers for any info

Sorry that I can't help, but could you tell me how much the non-cat down pipe costs? Mine has a repair, and I guess it will need replacing sometime soon.

Is it an easy job, or does it need special tools and is time consuming?

no is the simple answer. if your car was fitted with a cat from new then it has to have a cat to pass the mot.

tonyw said:

Sorry that I can't help, but could you tell me how much the non-cat down pipe costs? Mine has a repair, and I guess it will need replacing sometime soon.

Is it an easy job, or does it need special tools and is time consuming?

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It is about £260 for the front pipe from Paddocks.
It should be a simple job, there are as I remember only 5 bolts (3 at the manifold end and 2 at the back join end)
I guess the only time consuming bit might be getting the rubber mount back on.

yella disco said:

no is the simple answer. if your car was fitted with a cat from new then it has to have a cat to pass the mot.

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That's interesting as "Twisted performance" and a local garage near to me say it's not a requirement for the MOT?!?!

try island4x4 they quoted me about 60 70 quid for decat

sparrowhawk said:

That's interesting as "Twisted performance" and a local garage near to me say it's not a requirement for the MOT?!?!

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do these garages both carry out mot's or are they both the sort of two bit back street garages that will prepare your car and then take it to an mot centre, charging you for the privalage. if they are mot garages then de-cat your vehicle and take it to them for an mot. if you look on the VOSA website it explains everything you need to know about mot ing a vehicle.

I've asked 3 well respected garages now and they have all said the same thing.
Ditch the cat! It'll save money, the car will go better with no detrimental effects and won't effect the MOT!
I guess I'll try it!

your call mate, i am just passing on advise that i was informed of.

ok, to put an end to this " a bloke told me" i was actually in the vosa testing station today so i asked the head man there about this. his exact words were " if the vehicle was registered after sept 01 1992and a cat was fitted when it was first registered then it must have a cat fitted to pass an mot otherwise it is deemed a fail" i hope this helps you

Cheers for that.
Guess I'll have to play by the rules then!
Bizarre how many variations of opinion there are!!!!!!!!

it all boils down to how high up the tree the man you know is. i would say being the centre manager at the vosa depot is pretty near the top

For my sins I am an MOT tester. The VOSA manager was correct in saying about CATS having to be in place if fitted as original equipment but that only applies to Petrol vehicles not Diesels. Diesels are only tested for particals of smoke emitted out of the tailpipe wheras the petrol analiser has to measure the effectiveness of the CAT by the CO gases / Lambda and HC content.
Barry

nice one stig, so basically if yer have an oil burner yer dont need the cat, welcome ter the mad ouse by the way

I thought about removing the CAT on mine so asked a friend in the know, he said it's not a CAT as such but a DPF (Diesel Particulate Filter) only on the newer generation of diesels does the DPF also act as a CAT (ie, removes or converts gasses), the older type is basicly just a filter so removing it may increase the particulate count and cause the vehicle to fail the mot, it would also give you a pretty much straight through exhast system, good for performance but noisier.

I had a quick look on google and this does seem to be the case.

I suppose it depends on how much soot your engine is chucking out in the first place ?

Yella is right!
If the vehicle had one then its needs one for MOT. An aftermarket cat should cost you between £150 and £170 for a decent one that will last. Bosal are quite good. Fitting is a piece of cake.
Looks like there was a cat and non cat version of the exhaust
You could fit the non cat pipe (it does go on)but that does not have a hanging bracket on it and would fail the MOT for not having a hanger when there is fitting point on the vehicle to take one that should be there.

Today I MOT tested a 300tdi equipped with an egr valve and a "cat", the smoke emissions gave a reading of 0.19ppm (limit is 3.00ppm for Turbo) so I then tested my own 300tdi no egr and no "cat" (early 300 and not fitted by the factory) and that gave a reading of 0.35ppm. I think a lot depends on the condition of the injectors/filters and pump timing being correctly set up + the vehicle being driven hard on the road before it is presented for test (so as to clear any soot residue from the silencer box and tailpipe). If a vehicle fails the emission test and is left with us to sort it, it usually has an injector cleaner put in with the fuel and is then left running at 2.5k revs for 15 minutes and this always works at removing the soot content of the exhaust and it then passes with flying colours. Hope this information is useful. Barry

nice one stig, any chance of a not so strict test

Yella all MOT tests are supposed to be done to the same standard!!!!!! We are located in the NW and carry out tests for 2 different LR specialists, I think it is because I have an understanding of the beasts ( I have over the last 32 years owned 12 variants). Any tips that you may want on passing the test just mail me. Barry

Cheers Stig,
Thanks for the info and hopefully will get my Disco suitably prepared for it's next MOT.
Cheers again.
Martin