MR2 Roadster Owners Club

The Workshop => Maintenance, Problems & Troubleshooting => Topic started by: AckersMR2 on June 7, 2012, 13:37

Title: Precat and the MOT?
Post by: AckersMR2 on June 7, 2012, 13:37
I know lots of people have removed their pre cat, me included, either by way of gutting it or fitting a CHE type manifold. I was looking for info on something else today and came across an article about the new MOT rulings that came into affect this April, and one of them being this:

Exhaust
A catalytic convertor fitted as original equipment but missing will be a reason for failure.

Now obviously most MOT stations including Mr.T probably will not have Mk3 MR2 experts working there and as far as they are concerned as long as the main cat does its job and reduces the omissions then thats fine but if someone did look in my engine bay (no heat shields fitted) and said "theres supposed to be a catalytic converter fitted there" then would that mean it would fail? Or does this rule assume the vehicle only has one cat and you have removed it?
Title: Precat and the MOT?
Post by: AmeR on June 7, 2012, 13:47
I would have said that the main cat is the real concern. They would have to pop out the O2 sensors to check and I'm sure they're not meant to do that.

I'd say we need a guinea pig! Who's MOT is up soon?  s:lol: :lol: s:lol:
Title: Re: Precat and the MOT?
Post by: onion86 on June 7, 2012, 13:54
Pretty sure that only means a main cat, I very much doubt they would care/check for something that's only on the car for the US market.
Title: Re: Precat and the MOT?
Post by: krazysteve on June 7, 2012, 14:07
Hi, i don't think pre cat performance is checked.
Your engine should be nice 'n' hot before going in for the test ( take it for a italian tune up)
Ours went through last year ok (pre-cats removed), even with it burning oil in vast amounts.

 l viewtopic.php?t=11393 (http://www.mr2roc.org/phpBB3/viewtopic.php?t=11393) l
Title: Re: Precat and the MOT?
Post by: onion86 on June 7, 2012, 14:12
Quote from: "krazysteve"Hi, i don't think pre cat performance is checked.
The question isn't the performance of the car without them (probably 80%+ people on here don't have them) it's the fact that whether you pass an emissions test or not if you car was fitted with a catalytic converter it has to have one present for the test as per the new rules; so the question is whether that stretches to the pre-cats or just the main cat.
Title: Re: Precat and the MOT?
Post by: MelBee42 on June 7, 2012, 14:17
Mine got MOT'd after the new rules came in (by two places, no less!) - no problems at all with the fact my pre-cats are removed.
Title: Re: Precat and the MOT?
Post by: Anonymous on June 7, 2012, 14:20
TBH (and i know this is a legal subject) owning a rotary engined car now means you simply CANT pass emissions test from a 'Normal' garage full stop! This involves inclusion of CATS all you like.

As long as the car is hot, the pre-cats are meaninless. most if not all MOT stations are looking for the magic fail figure or it passes. For the rest of us pumping out some serious fumes, always best to know someone lol

*disclaimer, I dont break the law nor do i suggest anyone does  s;) ;) s;)
Title: Re: Precat and the MOT?
Post by: FGrob on June 7, 2012, 14:25
Pre-cats are just that precats, nothing to do with the main cat fitted to your car, remember this engine is also fitted into other models which don't have precats fitted, the only reason we got them is because of the Yanks.

I run a sports cat which has been tested at Toyota for the last 3 years, the thing is it's fitted with a cat which is what the law is looking for, it's those that don't who will fail.

Rob.
Title: Re: Precat and the MOT?
Post by: AckersMR2 on June 7, 2012, 14:38
Quote from: "onion86"so the question is whether that stretches to the pre-cats or just the main cat.

My point exactly.
I'm sure it would be fine, and for those who gutted their standard manifold their not going to go taking the 02's out looking for them, it's just if in my case they look at my CHE manifold (no heat shield) and ask wheres the pre cat gone? and then go getting all "Captain Mainwearing" on you and say (in my best train spotting accent) "The rules stipulate that "All" manufactures catalytic converters must be present and working, as you have seen fit to remove the device, I, in compliance with the rulings of the department of transport, shall be failing your vehicle today"  s:lol: :lol: s:lol:

I read of some people who have removed their cat, don't have one at all and the vehicle still passes the emissions test, if that is true then this new ruling must mean that an additional check beyond just the emissions is made to make sure that the/a Catalyst is present. If that is the case then will they have some sort of database on vehicle Cat's for the examiners to check against or will it just be up to their experience to find it?
Title: Re: Precat and the MOT?
Post by: mrzwei on June 7, 2012, 17:11
They are not required and so won't, remove anything to check it.
Title: Re: Precat and the MOT?
Post by: puma2 on June 8, 2012, 00:44
mine past mot day before ding day. pre cats out new main cat fitted pass  s:D :D s:D  
as far i no and what other people are saying pre cats should not matter, main cat yes,

spoke about new mot laws with them, some of the laws have bean bean back again for latter this year others just at the mo are advisable
Title: Re: Precat and the MOT?
Post by: stargazer30 on June 8, 2012, 07:41
How about a 2 that has a metalic pre cat but no main cat   s:shock: :shock: s:shock:    Think thats pushing it for the MOT?   s:mrgreen: :mrgreen: s:mrgreen:
Title: Re: Precat and the MOT?
Post by: Steve Green on June 8, 2012, 08:28
Very few cars have pre-cats. Most garages wont know they are fitted in an MR2 and for an MOT test they are not allowed to dismantle any part of the car so unless you have fitted a Che manifold they wont know that a change has been made.
Title: Re: Precat and the MOT?
Post by: AckersMR2 on June 8, 2012, 08:52
Quote from: "Steve Green"so unless you have fitted a Che manifold they wont know that a change has been made.
s:shock: :shock: s:shock:    s:scared: :scared: s:scared:    s:lol: :lol: s:lol:
Title: Re: Precat and the MOT?
Post by: ianfsb on June 9, 2012, 12:38
AFAIK the precats are there to increase the temperature of exhaust gases BEFORE these reach the Catalytic Convertor itself.

The object of this exercise is to increase CatCon performance from cold start and thus allow for a "low emmissions" tax bracket in the USA.

It's my understanding the precats perform no emmision reductions whatsoever.
If they did they'd be absorbing the noxious stuff which the CatCon is designed to do and in due course would also need to be replaced...

Precats are not a "replacement part".

Happy to be corrected though...
Title: Re: Precat and the MOT?
Post by: Gif on June 9, 2012, 12:56
Think the other thing to consider here is that most MOT inspectors are doing their job on the basis of why the MOT is there.  To ensure the vehicle is roadworthy.  Now we all know that emissions are deemed to be a sign of roadworthiness these days but to be honest, if an MOT inspector doesn't spot the lack of a cat, it's not gonna kill or seriously injure anyone before approximately January 28th 2386 when the giant tornadoes start hitting the western seaboard of the US.

So are they really going to worry about a missing cat?  Miss a bald tyre, a split brake hose, a leaking fuel tank, a duff shock, a broken spring, a rusty sill then you might just have a problem with the resultant investigation by the MOT following the inquest. Nobody's gonna die cos they got hit by an MR2 without its pre-cats, so the consequences are nil and the level of diligence therefore marginally less than that I would suggest.
Title: Re: Precat and the MOT?
Post by: g5elb on June 9, 2012, 13:01
My 2 flew it`s MOT test last wednesday and the pre cats had been removed 2 months ago.and a silverstone perfomance free flow exhaust fitted.