Catalytic Converters

[rtbcomp]

From what year was it mandatory for cars in the UK to have catalytic converters fitted?

Thanks!

 

[Hitch]

From vague memories of an exhaust course, it was J reg.... someone else will hopefully confirm/disagree

 

[BChild]

From vague memories of an exhaust course, it was J reg.... someone else will hopefully confirm/disagree

J's don't need cats

Cats were fitted on some cars as early as 1987 not mandatory till K reg so 1992 on a K needs cats

There are some work arounds but I'm not stating that on a public forum

 

[Rick]

Hmmm, i don't think there mandatory at all, you have to have the emissions tested for a "cat test" or "pre cat test" on a 93 or newer, unless the engines out of an earlier car from what i remember.

But I don't think you actually need a CAT, just VERY hard to pass without 1.

 

[hotrodder]

Cars registered after 1 Aug 1992 have the 'cat test'. As above, don't think cats are a legal requirement but you've little chance of meeting the emissions requirements without. Older cars are tested to the pre 92 emission limits of 3.5% CO and whatever the HC limit is regardless of whether a cat is fitted

 

[Rick]

Cars registered after 1 Aug 1992 have the 'cat test'. As above, don't think cats are a legal requirement but you've little chance of meeting the emissions requirements without. Older cars are tested to the pre 92 emission limits of 3.5% CO and whatever the HC limit is regardless of whether a cat is fitted

I think its something like 0.2 CO on the cat test, HC 400ppm and 0.97-1.05 lambda. As you can see with the CO levels the difference between cat and none cat is massive.

 

[rtbcomp]

Thanks for hrlp guys.

I'm looking at a J-Reg Volvo 240 estate to replace my dead 760 GLE and I don't want the potential cost of replacing the cat sometime in the future

 

[BChild]

Thanks for hrlp guys.

I'm looking at a J-Reg Volvo 240 estate to replace my dead 760 GLE and I don't want the potential cost of replacing the cat sometime in the future

Just make sure it doesn't have lambda both before and after the cat - it gets very tricky to get round the EMS when it has a double lambda arrangement

PS - I run an R reg with no cat for 11.99 months of the year - it just gets fitted for an MOT

3 mpg better consumption
Manifold flexi joint replacement every 18 mths if cat is permenantly installed (a fair bit extra weight hanging on the downpipe

 

[Justme]

Can you still remove the CAT if you convert to LPG? I think that used to be one of the ways round it. Mind you a new CAT can be quite cheap now compared to what they used to cost.

 

[rtcosic]

Just make sure it doesn't have lambda both before and after the cat - it gets very tricky to get round the EMS when it has a double lambda arrangement.....3 mpg better consumption

Talk me through that slowly!

With a (functioning) cat you need to run near stoichometric for the cat to operate correctly. Without a cat (or a non-functioning cat) you can retune to a leaner map and gain around 10% improvement in fuel consumption (at the expense of deseasel levels of NOx).

I suppose there is also a lower backpressure without the cat.

So can you 'remap' the ECU (EMS) on your vehicle for stoich with cat and lean without cat maps? The Rover MEMS can't be 'hacked' to do this unfortunately.

 

[chunkytfg]

for the record i have a K reg mini and the exhaust i pulled off it last weekend didnt have a cat on it

 

[Robotstar5]

A friend of mine gets quite few TVR owners in for him to refit the cat, get it MOT'd then remove again.

 

[BChild]

Talk me through that slowly!

With a (functioning) cat you need to run near stoichometric for the cat to operate correctly. Without a cat (or a non-functioning cat) you can retune to a leaner map and gain around 10% improvement in fuel consumption (at the expense of deseasel levels of NOx).

I suppose there is also a lower backpressure without the cat.

So can you 'remap' the ECU (EMS) on your vehicle for stoich with cat and lean without cat maps? The Rover MEMS can't be 'hacked' to do this unfortunately.

The cat is also a very efficent silencer - Blockage but as the rest of the system is still std the back presure reductions isn't huge

I've not changed the EMS settings (requirement to preserve the cat) car runs absolutely fine without the cat fitted - slightly more bottom end and you can short shift much earlier - it doesn't feel as asmatic - in fact for the hour I have to drive it with the cat fitted I hate it!!!

I ran a Vauxhall 3.0 24V for 6 years with the cats off and mpg was miles better - my LC is decatted but thats more for sound

 

[shenion]

Backpressure depends on the cat size.

My Mustang has 4 cats on it (dual exhaust). Many just remove the mufflers for more power I went with a FLowmaster cat-back exhaust. Runs well and is not too loud.

27MPG highway on a V8 (that's US gallons)