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The mkiv Supra Owners Club

Decat MOT query/ BPU without decat


rossky

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Hi all,

 

Unfortunately in Ireland cars over certain year hav to do an MOT every year, so I presume the Supra will fail the MOT with the 1st decat out, I think.

I have at the minute the first decat in with second decat remove and a HKs super dragger which all passed the MOT.

 

I know want to do a complete BPU but really dont want to be puttin in a 1st decat every year for the MOT as that will just annoy me, what do you guys do? When I had a GTR japspeed done a decent Highflow cat which would be ideal but I cannot find one anywhere for the supra.

 

So worst case scenario how does the car perform to BPU with the 1st cat still in?

 

Look forward to yer thoughts?

 

RC

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Guest Roger NE

Certainly here in the UK there is no legal requirement to have a Cat fitted . . . (and if an MOT garage tries to tell you otherwise, they are WRONG!)

 

It's just that post 1993 cars have to pass what is normally referred to as a CAT Emissions test . . . it just means that the emission levels it has to pass are much lower . . . but my car passes them fine without ANY Cats fitted !

 

(I would imagine the rules in Ireland are very similar)

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Guest Roger NE

Well they shouldn't have to be "friendly" . . . as they're doing nothing wrong!

 

It's just that some of them don't properly understand the Regulations.

 

Any Supra should pass the "CAT Test" without any Cats fitted . . . and the figures for the "Non-CAT" test are absurdly high !

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Well they shouldn't have to be "friendly" . . . as they're doing nothing wrong!

 

It's just that some of them don't properly understand the Regulations.

 

Any Supra should pass the "CAT Test" without any Cats fitted . . . and the figures for the "Non-CAT" test are absurdly high !

 

I believe some Supras may not need to have the cat test, but not all.

 

My local MOT tester showed me the official info that stated that my '95 UK Supra was supposed to pass the cat test.

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Guest Roger NE
My local MOT tester showed me the official info that stated that my '95 UK Supra was supposed to pass the cat test

 

Sure . . . but the point I'm making is that your 1995 UK Supra a) Doesn't actually need to have any Cats fitted, and b) it should be capable of passing the "Cat Test" figures WITHOUT any Cats fitted.

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interesting. the emission laws here are dependant on year of manufacture so my 99 is expected to have co below 0.5 %. Car test centres here are pretty strict as there was a watchdog show that expossed all the bribery recently ha! My old GTR was a 91 so its emisssions band was much higher.

So firstly does anyone know wot the Co's will read with all cats removed?

2 has anyone had a Car bpu'd and left at cat in if so how did it perform?

 

Trust me if i have my way the cats will be staying out

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Guest Roger NE
So firstly does anyone know wot the Co's will read with all cats removed?

 

It obviously depends on how accurate your fuelling is . . .

 

Mine (with no Cats fitted) was 0.1% CO at 2500 RPM and 0.2% at idle . . . EASILY passing the CAT Test ! (even though it's only required to pass the Non-Cat Test)

 

If yours is higher than that, first thing to do is replace the Lambda Sensors

Edited by Roger NE (see edit history)
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Roger, is it not a case that your MOT tester is one of the 'friendly' variety?

 

Mine hasn't any cats installed and what you might call the 'official' printed emission readings (cat test) show a pass, but it actual fact it wouldn't pass is done exactly by the book... and it has brand new lambda sensors, runs very well and returns good MPG.

 

If all Supras should pass the cat test emissions without cats, then why would many people bother to refit the second cat if their MOT station wasn't that 'friendly'?

Edited by SteveC (see edit history)
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Guest Roger NE

Because, sadly, a lot of MOT Testers don't understand the Legislation !

 

There is actually no requirement for ANY car to have a Cat fitted . . . just a requirement to be below the relevant Emissions for that Vehicle / Year band

 

Some people print out the Rules from one of the Gov websites and take it along to show them !

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Any Supra should pass the "CAT Test" without any Cats fitted...

 

This is what I was referring to in my last post.

 

All Supras that are running correctly (and with new lamba sensors) will not pass a correctly performed cat emissions test without a cat fitted.

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I am under the understanding that if a car was built/manufactured with a cat it must have one:taped:. Rules for MOT's have had subtle changes over the last few years. I am also under the impression that noisey exhausts are also being targeted.:search:

 

Manufactures employ the use of a cat to lower emissions to pass its tests, so by removing it should usually fail thus creating high emissions being vented into the atmosphere which is very much frowned upon by environmentalists. If it doesn't pass the legislation expect to be ordered for a retest MOT or fined by police.

For whatever reasons Toyota put two cat converters on (maybe for emissions legislation in Japan :tomato:) the car only needs one after 31 July 1995 to pass emissions and none to pass the Non cat test before 31 July 1995. Regardless if your tester is friendly or not, once your car details are entered he can do F all about the emission results as its all registered on computer, Unless he doesn't notice you reverse another car in when he goes to the toilet.

 

 

This is where a friendly tester comes in:


    Loudness of an exhaust should not be louder than a standard car, this can be overlooked.
    Smoke can also be overlooked.

 

 

Everything you need to know is in the link below.

In-service exhaust emission standards for road vehicles: 17th edition

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So what about the Reason for Rejection that says "Catalytic converter missing where one was fitted as standard"?

 

And pre '95 vehicles that are NOT in the emissions book/machines are NOT subject to a full cat test. It goes like this..,

 

BET test > 0.20% CO/200ppm HC/0.97-1.03 Lambda @ 2500rpm - 3000rpm

 

Used from 2002 > = 0.20% CO/200ppm HC/ Lambda can vary according to manufacturers specs @ 2500rpm - 3000rpm

 

Used from 08/95 = 0.30% CO/ 200ppm HC/ again Lambda can vary @ 2500rpm - 3000rpm

 

Used from 86-95 = 3.5% CO/ 1200ppm HC - NO lambda @ idle

 

Used from 75-86 = 4.5% CO/1200ppm HC - NO lambda @ idle

 

Pre 75 = visual check.

 

So basically, pre '95 with NO emissions related data = pre-cat test and CAN have cats removed.

 

95 > vehicles with NO emissions related date = 95 > 02 CAT test. Also, MUST have a cat fitted where one was fitted as standard.

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