Will my car pass the MOT

[crazymatelot]

Guys some advice please. My Cerb has two cats and a sports exhaust. Is this enough to pass the MOT or will the car be too loud? It went through the MOT last year with this setup, but is going somewhere else this time, although it is going to a TVR specialist.

[falcemob]

"Too loud" is subjective and down to the tester. I wouldn't fail a car for too loud unless the exhaust is blowing really badly or it's just too loud.

[kojak]

Take it back where you went last year.

[crazymatelot]

It's going in for a 12000 mile service plus a few bits and pieces. I need it before the 20th Sept cos it's going to Goodwood that weekend, and I can't get it booked into the original place before that. So I suppose I'll just have to chance it.

[Byker28i]

Shouldn't be a problem at all. The cats will knock down the emmissions and drop the noise by 8-10db.

Noise is subjective. I think the test just says something like 'not too loud'. A collegue at work just got his old pontiac GTO MOT'd with straight through pipes.

Edited by Byker28i on Sunday 24th August 08:09

[falcemob]

I assume it's a V8 in which case it would be pure music, not noise.
BTW does it have any other silencers on apart from the cats?

Edited by falcemob on Sunday 24th August 09:11

[trackcar]

I used to be an MOT tester and can't remember the exact wording but it's something along the lines of : the exhaust shouldn't emit more noise than an otherwise standard exhaust in good condition.

Fortunately for us most MOT stations don't know what a standard TVR exhaust looks like so sports pipes look normal to them, and they expect them to be noisy anyway! also most MOT stations are just happy to see something other than mondeos and vectras so I think you'll be fine

[Byker28i]

falcemob said:

I assume it's a V8 in which case it would be pure music, not noise.
BTW does it have any other silencers on apart from the cats?

Edited by falcemob on Sunday 24th August 09:11

Trouble is these days every Nova, Saxo, Imprezza, etc has a dustbin size exhaust on the rear, so in the eyes of the public, it's often a fine line between music and noise. I think having such good looking cars though tip the balance our way

[crazymatelot]

falcemob said:

I assume it's a V8 in which case it would be pure music, not noise.
BTW does it have any other silencers on apart from the cats?

Edited by falcemob on Sunday 24th August 09:11

Apart from the two cats it has a sports exhaust, which I assume are two boxes but no baffles.

Many thanks to all who have replied. I reckon it will be okay and go through, fingers crossed.

[falcemob]

Byker28i said:

falcemob said:

I assume it's a V8 in which case it would be pure music, not noise.
BTW does it have any other silencers on apart from the cats?

Edited by falcemob on Sunday 24th August 09:11

Trouble is these days every Nova, Saxo, Imprezza, etc has a dustbin size exhaust on the rear, so in the eyes of the public, it's often a fine line between music and noise. I think having such good looking cars though tip the balance our way

There's a world of difference between a ropey four pot with a dustbin on the back and a V8 with straight through silencers.

[Mars]

trackcar said:

I used to be an MOT tester and can't remember the exact wording but it's something along the lines of : the exhaust shouldn't emit more noise than an otherwise standard exhaust in good condition.

Fortunately for us most MOT stations don't know what a standard TVR exhaust looks like so sports pipes look normal to them, and they expect them to be noisy anyway! also most MOT stations are just happy to see something other than mondeos and vectras so I think you'll be fine

When I got mine MoT'd they questioned me on that principle, but I just told them that ALL TVR's sound like they're straight from Hell. They weren't convinced but considering the effort we'd all gone to to make it emissions-compliant, I think I'd worn out their "objections" meter and it passed.

[Ireland]

Slightly off topic but do any of you know what sort of emissions reading there is with both the standard exhaust and the sports one (both with the cats fitted)?

The Irish NCT is way stricter than the MOT and mine will be heading in for it soon enough.

I'd like to be fore-warned in case I need to lean off the fuel mixture for the test.

[falcemob]

Ireland said:

Slightly off topic but do any of you know what sort of emissions reading there is with both the standard exhaust and the sports one (both with the cats fitted)?

The Irish NCT is way stricter than the MOT and mine will be heading in for it soon enough.

I'd like to be fore-warned in case I need to lean off the fuel mixture for the test.

From memory it ranges from nighmare to wont pass.

[crazymatelot]

Ireland said:

Slightly off topic but do any of you know what sort of emissions reading there is with both the standard exhaust and the sports one (both with the cats fitted)?

The Irish NCT is way stricter than the MOT and mine will be heading in for it soon enough.

I'd like to be fore-warned in case I need to lean off the fuel mixture for the test.

Last MOT mine came in (Passed) with the Catalysers and sports exhaust with 0.08% CO and 31 PPM on Hydrocarbons. The limits according to the MOT readout are less than 0.30% on the CO and less than 200 parts per million on the hydrocarbons. Is that any help?

[Mars]

CO is supposed to be 0.3% from memory. Mine originally read 4000. Yes FOUR THOUSAND.

Fair-enough, that was without the Cats but even when we put them on it only dropped to 3900-ish.

I lowered the fuelling, advanced the igntion (about 20 degrees) and got it into the hundreds. I was all about to give up when they suggested I take the car for a warm-up run, so I did (after resetting the fuel and ignition). Then we retested it WELL UNDER then limit (again after compensating for fuel and ignition), however with all the compensation-changes I'd made, I couldn't keep the engine running long enough to allow them to connect their computer to the DVLA's computer. Fortunately the garage was broad-minded and let me off with a pass from their own computer read-out.

[falcemob]

crazymatelot said:

Ireland said:

Slightly off topic but do any of you know what sort of emissions reading there is with both the standard exhaust and the sports one (both with the cats fitted)?

The Irish NCT is way stricter than the MOT and mine will be heading in for it soon enough.

I'd like to be fore-warned in case I need to lean off the fuel mixture for the test.

Last MOT mine came in (Passed) with the Catalysers and sports exhaust with 0.08% CO and 31 PPM on Hydrocarbons. The limits according to the MOT readout are less than 0.30% on the CO and less than 200 parts per million on the hydrocarbons. Is that any help?

That sounds like the standard limits set by the computer, there may be different ones in the data book for the extended CAT test.

[Byker28i]

falcemob said:

From memory it ranges from nighmare to wont pass.

Really? never had a problem with mine.

Mot was at the beginning of this month
Fast Idle CO was 0.009% (need to be less than 0.3%), HC was 40ppm (need to be less than 200ppm)

Natural Idle CO was 0.024 (needs to be less than 0.5%)

[Ireland]

This is what I have ahead of me .....

http://www.ncts.ie/nctmanual.pdf

I reckon I'll struggle to pass it.

They are completely separate to all the garages over here so there's no hope of having the exhaust pipe of a MIcra used to get the Cerbera reading.

But I'm sure that never happens in the UK either.