Has anyone a 2.8 petrol catalytic convertor that is faulty going spare /for sale please???

John

Er...

You want a faulty one...? :confused:

Im guessing for exchange.

Yes I want a faulty one to replace my good one with. (Running on gas is so much cleaner that its not needed so I want to gut the faulty one) get more usable power then.

I always was daft..................................................

Yes I want a faulty one to replace my good one with. (Running on gas is so much cleaner that its not needed so I want to gut the faulty one) get more usable power then.

Ah, that cleans it up so to speak!

Wouldn't it make more sense however to use a cat bypass pipe?

And in any case, the year of your car... doesn't that mean it has to have a cat in place regardless?

Can u get a bypass pipe?? The Mot man told me as long as the emissions are ok it was alright.

i want to keep my existing one intact so that I have it if needed.

Thanks all

J

Can u get a bypass pipe?? The Mot man told me as long as the emissions are ok it was alright.

Yes, cat bypasses are available - or a good custom exhaust dealer will build you one with the correct flow characteristics. Indeed, cat bypassing is common amongst performance car followers - look at the ones available for a 106 GTI, for example.

However, having had a conversation with VOSA when I had a problem with my cat on, er, my 106 (1.4 XSI) - it appears as though the ruling on cat's is somewhat complicated. Here's my understanding and apologies in advance if my dates are wrong, this is from memory...

When they were first introduced, cars had a new emissions test written. There are therefore two tests for many cars - one with cat and one pre cat. In my case, my 1993 106 XSI had both these tests available to the MOT tester. In terms of the law, if the car passed whichever test the station selected - it passed. Regardless of the cat, there, not there, faulty, etc. The law also "advised" that if the car had a cat, the station "should" use the cat test - although it that test was "unavailable" for any reason then a non-cat test for a catted car was OK.

After this evidently grey law, the presence of a cat was made law in approximately 2002 (I think). The law now states that if a car was fitted with a cat originally (which of course they now all are at this point), it has to be fitted and the vehicle has to pass the stricter emissions test. This only applies to cars registered after that date.

Interestingly, this doesn't seem to apply to diesels. Cats fitted to them are not required to be fitted at MOT time - and indeed what they actually do (support a chemical reaction to convert harmful gasses into water) is of limited effectiveness on a diesel.

So, in the case of a petrol Superb - come MOT time, a cat has to be fitted - or at least that's my understanding of the law.

My 106? The cat was shafted. I took it out - it still passed. To this day I believe it's still used on a daily basis, still with no cat and still with the stainless system I fitted.

Spark ignition engines have to pass a gas based emissions test at MOT time. Nearly all makers use a catalyst in closed loop mode to ensure compliance.

Compression ignition engines (diesels) currently only have to pass a smoke test. Although fitted with an oxidation catalyst in open loop mode, VAG engines will pass the present MOT test without it.

I have never been a fan of LPG conversions and all of the ones I have dealt with have caused long term trouble, either to the LPG system itself or to the engine (valve seat damage). The loss of spare wheel space, patchy availability and a tax system which is about as predictable as the weather just puts the lid on it.

The diesel engines available in most VAG vehicles (the engine is easily the best feature of my Superb) makes an LPG conversion senseless.

rotodiesel.

Thanks for the info. very instructive - its really why I wanted a shot cat ( I quite like cats) to see if it passes emission test.

I still prefer petrol to diesel ( I run d. vans) but time will tell as to lpg reliability.

Yes tax is unpredictable but dont see petrol tax coming down.

I am trying to be positive - Its raining but looks as if it may stop, recession has begun but the end must therefore be nearer ummm thats all I can think of right now, any other ideas?

Cheers

JJ