Replacement exhaust - emissions?

[Ledaig]

I'm thinking about getting one of the stainless sports exhausts from here:

RimmerBros

As this would mean loosing the cat's, does anyone know how this would effect the ability to pass the mot test for emissions?
The information on the site regarding registration dates and mot's is a little confusing.

This will be going on a 1997 3.9 Discovery.

Cheers

[eliot]

I would say yes. I run megasquirt and I consider it "well tuned" and its well under the pre-cat emissions but miles over the "cat" emissions.

[Ledaig]

That's not the answer I'm looking for

Okay, so to build in some other options.....

The car runs on lpg and will be tested on this - anyone know if a cat is still 'necessary' to bring down emissions when running on this?

and

I keep finding some information online regarding vehicles with 6 or more seats (excluding the driver), not being classed as passenger vehicles and therefore needing to pass less stringent emissions tests – is anyone aware of this and know if it applies to a 7 seater discovery?

Cheers

[Liszt]

Depends where you take it but probably all right.

HAve a read hereof past experiences http://forums.lr4x4.com/index.php?showtopic=15606

[Ledaig]

Liszt said:

Depends where you take it but probably all right.

HAve a read hereof past experiences http://forums.lr4x4.com/index.php?showtopic=15606

Thanks - I did find that thread in a trawl of the web. As with most though, peoples experiences seem to be mainly limited to the TDi rather than the V8

[eliot]

Ledaig said:

The car runs on lpg and will be tested on this - anyone know if a cat is still 'necessary' to bring down emissions when running on this?

That may make difference i believe - you need to trawl the DVLA.

[Ledaig]

Been doing a little more digging on this.

It looks like the 6 or more passenger seats option is now 8 or more seats - probably due to the number of vehicles now with 7 seats as standard.

However, I have found a thread on the following site:

http://www.lpgforum.co.uk/

which states the following:

aboard_epsilon said:

Posted: Fri Feb 15, 2008 4:36 pm Post subject: Information about MOT's on Cat Equiped Cars

A good half of the mot stations around here in north wales are not clued up about testing cars made after 95 with cat on LPG

most say ...its a cat car .......its made after 95.......and it is to be given the full test ..for 0.5 percent CO

And will argue , when you tell them they are wrong.

They are wrong ...


I've just been on to VOSA about this ...

The rules are, if its got a cat .........made after 95 . (not sure what the cut off date is ...but rule applies to my 96 car ......and probably up to 2002)

if it's presented on LPG .......then it's to be given the non cat test .....with emission limit of 3.5 percent CO

if they argue

tell them to look it up in the manual ..they have

SECTION 7.3 PAGE 6

I can't post a direct link to the thread for some reason

I'll try to look into the implications of the above myself, but if anyone knows a friendly MOT tester who would let you take a look at the relevant section could you please do so and let me know the content?

Cheers

[Ledaig]

Well, the results are in so I thought I would post them up for interest, and also as a point for future reference.

The exhaust was duly changed for the Rimmer Bros stainless sports jobby, thereby removing the cat's. The only other change was the removal of the airbox in order to add a K & N filter.

Yesterday was D-day with the MOT

First off, the information I found regarding the LPG emissions was correct in that where presented on LPG, the vehicle will be tested to PRE-Cat limits. i.e. CO level = max 3.50% and HC level max = 1200ppm

So the results, last years first.

2007
Tested on LPG with original exhaust complete with cat's:

CO level = 0.76%
HC level = 238ppm


2008
New stainless exhaust - no cat's:

CO level = 0.63%
HC level = 225ppm


So CO is down by 17% and HC is down by 5.5% after removing the cat's.

Buggered if I know what's going on, but it works for me!!

[Steve_D]

Don't know the exact rules and cut off points but if it is similar to the rules for SVA test then the next cut-off point is 1 Oct 99. Before that it is as you were tested but after that it is the normal cat test i.e. CO 0.3 and 200ppm fast idle and CO 0.5 at idle.

Steve

[Ledaig]

Steve_D said:

Don't know the exact rules and cut off points but if it is similar to the rules for SVA test then the next cut-off point is 1 Oct 99. Before that it is as you were tested but after that it is the normal cat test i.e. CO 0.3 and 200ppm fast idle and CO 0.5 at idle.

Steve

Steve,

Not sure if or where the next cut off point is for LPG or even if there is one.
If it was tested on petrol it would be the figures you quote as it is a post '95 vehicle.
I only get the higher pre-cat limits due to the LPG test even though it's a post '95.

The obscure bit is the fact that the figures are lower this year without the cat's.

Surely they can't have been that knackered

[Steve_D]

Ledaig said:

.........The obscure bit is the fact that the figures are lower this year without the cat's.

Surely they can't have been that knackered

Not knackered but may have been clogged.

Steve