Removing cats...ECU pin 20 or 21

[DevonGSi]

I will soon be de-catting my 24v.

Im sure others have done this. What are the results?
Ive heard of it causing problems.

Do I need to ground pin 20 (or 21) when they come off?

Thanks

DevonGSi

[melinx]

It says pin 20 in the link below under "ECU coding wires (where fitted)"

http://www.opelclub.sk/upload/akonato/software/m15view.pdf

[carlton_mad]

ah yes but the new VOSA rules will make the removal of said cats an MOT fail!!

[DevonGSi]

ah yes but the new VOSA rules will make the removal of said cats an MOT fail!!

What new rules?

I thought if it was registered before 1993 or something it didnt need them?

Anyway muy Civic VTEC VTi is decatted and that passes...nice mot man! 

[von-opel]

Have a look at page 8 of this

http://www.dft.gov.uk/vosa/repository/MoT%20-%20Issue%2050%20-%20May%202011.pdf

If it had a catalytic converter when it was new....it has to have one now (or next year) also blue bulbs (for that 'xenon'' look) are out as are xenon aftermarket conversions.

[Johnny A]

Fuck that, dodgy MOT time

[24vman]

Fuck that, dodgy MOT time

What's new, knowing you    

[Johnny A]

Never needed a dodgy mot in the past

[melinx]

Have a look at page 8 of this

http://www.dft.gov.uk/vosa/repository/MoT%20-%20Issue%2050%20-%20May%202011.pdf

If it had a catalytic converter when it was new....it has to have one now (or next year) also blue bulbs (for that 'xenon'' look) are out as are xenon aftermarket conversions.

Does that apply to a replacement engine that wasn't designed to be used with a cat. though ?

[Dave the Builder]

good Question ....
I've got the early NON CAT engine in my 93 CDi
I guess that will be down to the MOT tester to decide 

[nightmare]

Have a look at page 8 of this

http://www.dft.gov.uk/vosa/repository/MoT%20-%20Issue%2050%20-%20May%202011.pdf

If it had a catalytic converter when it was new....it has to have one now (or next year) also blue bulbs (for that 'xenon'' look) are out as are xenon aftermarket conversions.

As long as the headlights have:-

A, washers/washwipers

and

B, level adjusters( For towing/heavy loads in boot etc).

OR, It must have a specially designed reflector , which means new headlights designed for HID.

Then as far as I could find out you CAN fit aftermarket HID kits.
Seeing as most of our carlton's have electric range adjuster motors and washwiper's on the headlights
we should be O.K.

Also its if it was fitted "at first registration as standard" Not an optional extra( as some ABS and catalytic convertors were)

On the subject of BLUE lamps/bulbs the police have to have SOMETHING that distinguishes them
I mean with all the unmarked cars they have how else are they going to know if they're chasing one  of their own 

[carlton_mad]

the leveling system must be automatic ie "self leveling"

[turbojo]

the leveling system must be automatic ie "self leveling"

thats you and me ok then!

[rrv8]

Pin 20 to ground for non cat coding , if it had a cat there is not normally a pin fitted
Pin 21 is manual or auto coding

[nightmare]

With reference to CAT's it doesn't go by the engine, it goes by the car.

E.G. if the car didn't have a cat when first registered then it doesn't need one. You can put a brand new ENGINE in it from a car that had a cat and you DON'T need to have one. Because the car doesn't require it, even if the engine was designed to have one.

If the car had a cat fitted when first registered and you fit an engine from an older model that didn't have a cat YOU WILL STILL NEED A CAT. Because the car requires it not the engine.

On the other hand if the car passes on the emissions and you have a box in your exhaust that LOOKS like a cat then it WILL pass the MOT(visual test only).

Hope you can make sense of that.

[Dave the Builder]

My carlton has an older engine (non cat) and is MOTed as non cat test (3.5% CO), I do have all the paperwork to confirm age of engine.
but then carltons are that old now that MOT testers probably don't remember if they have cats or not 
If it's got a cat then I recon the tester would put it through a full emmissions test including cat test.

[nightmare]

Have a look at page 8 of this

http://www.dft.gov.uk/vosa/repository/MoT%20-%20Issue%2050%20-%20May%202011.pdf

If it had a catalytic converter when it was new....it has to have one now (or next year) also blue bulbs (for that 'xenon'' look) are out as are xenon aftermarket conversions.

Does that apply to a replacement engine that wasn't designed to be used with a cat. though ?

YES if CAR had one when first registered.

[DevonGSi]

So do I need to fiddle with the pins?

[bootie3367]

I see the Uk is catching up with the rest of europe then. I found out about the 'has to have cats fitted' business last year, unknowingly I had been through and passed all previous tests over here without the cats. It wasn't until my lambda started to fail that I found out my car has to have them fitted as it had them as OEM when manufactured.
I just put them on for the ITV now. I know she will pass cos I go down to a friendly garage and get the emissions tested without them on first.......it's all good.
As for the pin business, I didn't touch mine when I de-catted and never had a problem.

HTH

[melinx]

It says pin 20 in the link below under "ECU coding wires (where fitted)"

http://www.opelclub.sk/upload/akonato/software/m15view.pdf

It does say "where fitted": I can only guess that there was a transitional period during the production run of the ECU's when they were designed to be used with cat. or non cat. cars

[kevinfourlegs]

We got 3 cats, JD and Brandy both black and sisters and Nibbler a black and white male rescued cat. Their emissions are clean as they go outside.

[melinx]

As for the pin business, I didn't touch mine when I de-catted and never had a problem.

I accept that you have never noticed a problem, but doesn't that imply that the generally accepted premise that the lack of back pressure produced by the presence of a cat requires a different engine map !

So why did they produce an ECU with the ability to switch between cat and non cat

Or perhaps the difference is only noticeable if you 'give it some 'ammer' 

[Dave the Builder]

The pre cat cars have a silencer in the front downpipe which would give the back preasure on the 2 litre blocks. the cat car downpipe is shorter but bolt on the cat and they are the same length. 

[kevinfourlegs]

The down pipes are a different length, but bolt a cat on the shorter pipe, they then are the same length?

If so, does that mean the centre section and the rear section on a non cat and the centre and rear section on a cat equipped car are the same?

[Dave the Builder]

As far as I know the mid and rear boxes are the same,(probably diffrent part numbers just to confuse everyone) but I've used mid and rear box off pre-face-lift non cat on my cat fitted carlton.