Ian Sutton

I finally got my Magnex de cat'd mid section fitted this morning to go along with my already fitted Scooby Sport back box and down pipe.I noticed that my local garage was displaying the MOT sign and so I mention to the mechanic that I was aware that my car (STI V5) would obviously need all the Cats back on to pass its MOT in 18 mths time.

I went to pick the car up an hour later, the mechanic informed me that the fitting went well and that he had also ran an emissions test free of charge (same as he runs for MOT).The car passed with flying colours apparently.

Can anyone give me an explaination for this?

The car was on reserve fuel, engine stone cold and only driven 150 yards from home to garage if any of this is relevant.

a very confused Ian

pslewis

It simply cant happen - so the explaination for the results is that the MOT emission test equipment was faulty 0R the mechanic was having a laugh!!
A modern car cannot possibly meet the emission standards without a catalyst if it could we would all be running cat-less I can guarantee it!!
By the way where is the oxygen sensor on the Impreza??? it needs to be retained to keep the engine control loop closed. But the idea of taking the cats off to run around and then re-placing them at MOT time does appeal rather - it should mean that the cats last the life of the car too!!
Peter MY00 DBM-5 DOOR

RON

I spoke to a fellow owner at Goodwood yesterday and he had the full monty as well, he also said that his car had passed a test! How can this be?
Ron

GavinP

I personally have my doubts on how a car would pass without any cats but at least you know where to get your car MOT'd from now on...

Thanks

Gavin

Greg Small

My 95 WRX RA passed the mot no probs. The cat is still there but the garage said that they couldn`t do a full cat test cos they couldn`t get a pick up from the coil.(car has a coil for each plug) and the emmisions were well within the limit.

Therefore I wonder if it would pass with no cat fitted.

Cheers Greg

Paul Wilson

Maybe the mechanic was being a bit subtle, like come here MOT time mate and we'll pass it for you
Lets put it this way, there are quite a few places you can get an MOT for a catless Scooby, for obvious reasons the location of these places cannot be posted, but just ask around at a meet.

Sonnyrider

I have a de-catted MY93 WRX which "passed" the MOT.

In reality it failed but the garage put my car a MY92(no cats needed).

It wasn`t much over the mechanic said @ the time if it had the cats it would`ve passed.

Mind you it did help I knew the tester

pslewis

The scooby can do many things - but even it cant re-write the laws of physics!!!!

No cat no MOT pass - simple as that

I've just had a thought - maybe the engine wasnt running !!!! I have seen some mechanics do some daft things ... as we all can do!!

Peter



[This message has been edited by pslewis (edited 25-06-2000).]

NICK OAKLAND

I took a South African built, 2 yr old Toyota Venture for a SVA test about test 6 months ago & it passed without a CAT or lambda sensor. As long as it complies with the set parameters they won't fail it.

Ian Sutton

Thanks for the comments guys, at least I know theres no fault with the car.And what ever the real outcome as someone said I know where to get that MOT done in the future.

By the way the performance is monster, not too loud a bit more popping and banging, better pick up.Well worth the £91-.I believe Road Runner Notts are the only supplier of the straihgt thru Magnex MS (sorry plug).

Cheers again lads ...Ian

Trout

iTrader: (1)

Peter (Lewis),

you are emphatic that an STi cannot pass the MOT without a Cat - can you enlighten me as the parameters you are using to base this statement.

AFAIK an STi would struggle to pass standard Type Approval emissions and so are judged on a different set of criteria - e.g. for SVA. Also for some of use with programmable ECUs I would have thought - but to be fair have not tested yet - that we can programme the car to be very lean and emissions low just for the MOT test itself.

Just a thought.

R

sam

I own a WRX which has had both cats removed and has a full MOT.
I have looked into this because i to was worried that the MOT was not carried out correctly.
At the present time because there is no WRX or STI on most of MOT testers equipment a cat test will not apply.
For more info please look at my previous postings.

pat

Just out of interest, I have tried to "pass" the emissions test with my car, on a PossumLink....

I got the carbon monoxide down to 0.16% and unburnt hydrocarbons down to 80ppm. Looking at the book, the criteria were 0.4% and 200ppm, respectively, so by those criteria it would pass. The fuelmix was rather lean at the time (lambda 1.15); any richer and both CO and HC went up, any lower and it would missfire, and hence HC went up again....

The only reason this might not pass is that that lambda really ought to be 1.00 for a three way cat to work properly and setting fuelling for lambda of 1.00, I would have passed CO but not HC... hmmm. So I guess it depends on the testing centre....

Alternatively, you can do the high idle test if it doesn't pass at low idle. This involves running the engine at 2500RPM, and IIRC, it passed even at lambda of 1.00 :-) Strange but true.....

Cheers,

Pat.

pslewis

Sam writes:-

At the present time because there is no WRX or STI on most of MOT testers equipment a cat test will not apply.

--------------------------------------------

Maybe this answers your question Rannoch??

As a Senior Engineer in the defence industry I am no stranger to strange phenomenon, indeed many are designed into weapons.

But the fact remains that a car tested for a CAT emissions test - if one is required for the MOT, CANNOT - repeat, CANNOT, pass without a working CAT in place - indeed it is illegal to run a car without a CAT if one was originally fitted - of course the police would not know!! ;-)

I removed the CAT from my CALIBRA and it went like a dream - so I know the benefits. It was a 1992 so didnt have to meet the strict emission levels.

Maybe 'GREYS' are not governed by the same rules??

Markus

This is interesting to me as my MY94 WRX Wagon, has, or so I belive, the standard downpipe, which has a cat in it(?), but it has a HKS Hiper center + backbox, thus removing the second cat that usually sits in the center section. The car when imported passed an MOT.

I was worried as well, as I don't want the darling to fail next year on emmisions.

BTW - if the car does fail on emmisions then what can be done about it???

Ian Sutton

Markus I know that in the later imports (as in my STI V5) the down pipe has the most important Cat and the mid section the lesser cat as far as doing there jobs concerned.

So maybe that answers the question.

..Ian

MorayMackenzie

Markus,

My previous car, a 96wrx, didn't have a cat in the centre section, my STI III didn't either, so maybe your car has always run with only one cat (in the downpipe). If this is the case, it should pass ok.

Moray

IWatkins

Regardless of what Mr. Lewis says, cars CAN pass the emission tests without a CAT. Simple.

In fact, my 1989 GT4 (that doesn't require a CAT by law) passes the emision tests for a car of modern (CAT's fitted) design.

My car did have a single (downpipe) CAT and after removal the drive was much improved. Emissions are mostly unchanged.

Cheers

Ian

pslewis

[QUOTE]Originally posted by IWatkins:
[B]Regardless of what Mr. Lewis says, cars CAN pass the emission tests without a CAT. Simple.

---------------------------------------------
Thanks for the above Ian - you have a little problem understanding what I am saying?

A car which requires a CAT by law and needs to meet the CAT MOT regs CANNOT and I wont say it again, pass the MOT - what is wrong with you??? I am NOT talking clapped out 1989 models - I am talking cars made in the last 3 years or so .... has that cleared up your mind?? - hope so ... most of my hair has now been pulled out ha ha ha :-)

If what you say was true - dont you think we would ALL be driving around without CATs??? of course we would!!!!

Regards Peter

[This message has been edited by pslewis (edited 28-06-2000).]

pat

Peter,

At the risk of enflaming the debate even further, perhaps we *would* all be better off driving around without cats...after all they do cause more pollution than they are supposed to prevent :-(

Cheers,

Pat.

Gethin

Well MY97 WRX passed without cats. Simple as that also.

DavidRB

Anyone had one of those random roadside emissions tests? As a Londonner, it's this test that worries me more than an MOT.

richm

Peeps,
The company I work for manufactures gas analysers used in MOT stations; the fact is that a post '92 test procedure (which ordinarily applies to catalyst fitted vehicles) will not be passed without a working catalyst fitted.
The only way to get a pass is by inputting data for the vehicle that defines it as a pre-'92, this will relax the test limits and allow a pass. The only reason this can legitimately happen is that he car does not appear on the database list and is then tested as a pre-'92 non-cat car. This situation mostly relates to imports that do not have a direct UK equivalent. Even this is up to the discretion of the testing station; if the car has obviously been built and first used after August '92 then the tester can legitimately choose to test it at post-'92 levels and it will not pass without a Cat. To get a pass the CO and HC levels need to be below limits AND the lambda reading needs to be within a tight window (nominally 1.00). I wish I had the actual figures to hand - sorry I don't at the moment.

Rich

pslewis

Thanks for that Rich - glad there are two wise men on this BB (you and I !!) ... phew thought that I was talking to myself until you came along and put the record straight ... thank you god !!

Hope you will now take notice of a 'man who knows'?? boys/girls?? Take note Rannoch ... IWatkins ... and Gethin !!! watch this space for more amazing facts you didnt know you didnt know and still dont know!!!

Pete

IWatkins

Pete Lewis,

Yes, my old motor may be "clapped out" as you say but hey still has more style than those poxy Subarus

Even without it's CATs it passes emission checks for year 2000 2L Turbo cars, easily.

But I also know many, many GT4 owners with St185s and St205s post 93 that have had all CATs removed and still pass the emission checks at MOT both in the UK, Belgium and worst test of all California, USA. Same goes for Supra owners. Simple.

You can say what you like, but the emissions of these cars CAN be below those required to pass emission tests.

Cheers

Ian

pslewis

None is so blind as those that will not see Ian

Cant convince you of the facts can I? If I said red was red you would disagree so I can't be bothered anymore

I wish I lived in your world where the laws of science and physics dont exsist

Best regards my little misguided soul

Pete

IWatkins

Pete,

You can convince me of facts easily as I am very open minded.

However, hard data supports the fact that cars that should be running CATs, and aren't, have still passed their emission tests. There are many examples from Scooby owners above plus my own experiences in the GT4 world.

At the last count, 8 GT4s that should have CATs and have none have managed to pass the MOT in their respective parts of the country. 2 GT4s I know to have passed Californian Smog test (I think the strictest in the world).

True, you could argue that in every one of these cases, the test equipment was faulty, misused etc., but I doubt it.

Red is red by the way, unless you are colour blind.

Ian

[This message has been edited by IWatkins (edited 03-07-2000).]

Bassem

Forgive my very late addition. Turbo cars in general can pass the sniff tests easily, but they must be up to operating temperature. Most cars are leaned out at idle a little to improve emissions. When they're cold though, they run rich to warm the cats up quick.

My brother's RX7 passes without cats in the US, which are a little stricter than the UK. And that's a disgustingly filthy rotary. All he does is drive it for 30 mins before testing it.

Bassem

RobinL

Pete,

Easy tiger - this is a forum for shared experiences and help from people who have experienced them.

There are new cars being produced without CATS. Caterham & Westfield - and they pass MOT's - but because they are low volume production (same numbers as SVA approved Scooby's) the test is not yet as strict (which will change in the last qtr of this year).

If you can get away with not having a cat, then do it - more performance and the cat will last longer !

Despite the laws of physics, there's always someone trying to ice skate uphill in the face of public opinion and it looks like public opinion is saying you can get a Scooby (which we all have a common passion for) through an MOT without a CAT.

Coool !!!

Trout

iTrader: (1)

Mr Lewis,

I see that being UberLieutenant Engineering Undermanager, or whatever it is you are does not seem to qualify you to be sympathetic to the same blindness (deafness) that you, in your sweeping statement, accuse me of

I asked you to explain what the parameters by which you make your statement. Replying that you are a whatever, does not actually work at the MOT test station.

Finally, you failed to convince me, or anyone else for that matter with the facts because you didn't offer any. Merely assertion. However I see that RichM has come up with a rational answer, a requirement for CO and HC levels at a lambda of 1.00.

Thank you also to Pat for enlightening me as to how manipulating the LINK may, or may not help in this situation.

R

[This message has been edited by Rannoch (edited 20-07-2000).]