Sports Cats, need a remap?

[LPH]

After almost 12 months of not using the car (for obvious reasons) I'm going to spend a bit of money on some TLC and upgrades. Booked in for stone chips and door handle corrosion to be sorted and thinking about adding a pair of sports CATs.

Can I just bung them on without any sort of remap? I realise that is might not the absolute max benefit but it won't do any damage? 4.3 with AM 400HP upgrade.

Cheers

[paulrog1]

Assuming the sports cats have a reduced number of cells per square inch you will need a remap as the emissions service light will come on.

The lambda sensors between the cats will see a reduced gas convertion rate so the car will think there's a fault.

Call Mike at Bamford Rose, they do these kind of things all the time.

[AdamV12V]

Suggest you watch this video from Mike at BR

[Manners79]

You'll 99.9% likely need a remap to avoid an emissions light, plus the remap gives other benefits too in terms of power delivery and 'accessibility' of the power in there (which I'm sure you're aware of anyway). My 4.7 was 'sports catted' and remapped at Bamford Rose, can't speak too highly of them. They use really good maps and tweak for each car so possibly the ideal answer for you as you've already the AM upgrade put on. The BR guys are all ex AM works and used to working on thse maps in considerable detail. No affiliation etc, just a happy customer (who grins every time I hear the fantasitc noise my car now makes).

[johns355]

Interested in doing this too on my 08 roadster, anyone know roughly how much BR charge including the remap?
Tia

[LPH]

Interesting comments - cheers

I was looking at a set of 'Harrison Signature' CATs from the USA. They seem to have a good reputation and apparently don't throw MIL lights....

A very detialled discussion / review here:

https://www.6speedonline.com/forums/aston-martin/3...

[BiggaJ]

LPH said:

Interesting comments - cheers

I was looking at a set of 'Harrison Signature' CATs from the USA. They seem to have a good reputation and apparently don't throw MIL lights....

A very detailed discussion / review here:

https://www.6speedonline.com/forums/aston-martin/3...

It's an interesting write up for sure however, what others have already stated and what I have also experienced whether you use BR or another well respected independent, the remap also does other things, they lean the car out a little as it runs quite rich anyway and also raise the idle a touch plus some other stuff that I cant recall right now.

Even though these Ken Harrison CATS appear not to se the warning lights ablaze on your dash, it would be worthwhile having the ECU mapped to make sure you are getting the best out of your upgrade and sort out a few AM pre-sets along the way.

[S1-NOS]

The BR map also removes the initial dead pedal feel on the throttle. That was programmed-in initially for emission purposes.

[NMNeil]

AdamV12V said:

Suggest you watch this video from Mike at BR

Isn't removing or tampering with emissions control equipment illegal?

[BiggaJ]

NMNeil said:

Isn't removing or tampering with emissions control equipment illegal?

In the UK, it isn't as long as your car can still pass the annual MOT. This does include measuring exhaust emissions which the 200 cell uprated CATS can still stay under.

[Manners79]

S1-NOS said:

The BR map also removes the initial dead pedal feel on the throttle. That was programmed-in initially for emission purposes.

This is a very noticeable improvement on my 4.7. I had the air intake upgrade done at the same time which also helps make the engine work a little more freely so I can't actually say for sure which bit of work resulted in which improvement, but it is not that simple anyway - it is more a 'sum of the whole' thing and for the difference in price (very little) it seemed logical to me to do the sports cats, remap and airboxes as one programme of work. There is then another stage which involves new exhaust headers but that is a step up in cost so I'll save that for the future.

I wouldn't want to pre-empt BR's pricing in public but suffice to say I was very happy with the price I paid, the quality of the work done and the results I got.

BTW mine is an 'early' 4.7 so actually has the sports cats that are usually fitted to the 4.3 as it only has the one set of cats. Later 4.7s had 2 sets (per side) so there is an alternative approach to simply delete the second set with strtaight-thru pipes. I know the OP has a 4.3 but worth highlighting in case others are reading this.

[AdamV12V]

NMNeil said:

Isn't removing or tampering with emissions control equipment illegal?

It is not illegal, but it is an automatic MOT failure in the UK.

That said it will take a test centre to know what the original setup was like in order to fail it, so it will really depend on where you get your MOT done.

[AdamV12V]

BiggaJ said:

In the UK, it isn't as long as your car can still pass the annual MOT. This does include measuring exhaust emissions which the 200 cell uprated CATS can still stay under.

That is incorrect I am afraid. It will fail an MOT if you have removed or modified any of the original manufacture's emissions control equipment. See Section 8.2.1.1 of the MOT handbook.

https://www.gov.uk/guidance/mot-inspection-manual-...

As I put above however, it all depends on if your MOT tester knows what the original setup was supposed to be.

[NMNeil]

"Under the Road Vehicles (Construction and Use) Regulations (Regulations 61(7) and 61A(3)) and the Road Traffic Act 1988 (Section 42) it is an offence to use on a road a vehicle which has been modified in such a way that it no longer complies with the air pollutant emissions standards it was designed to meet."
https://www.gov.uk/government/publications/modifyi...
So it may pass the MOT with flying colours, but still be illegal.
Talk about confusing.

[AdamV12V]

NMNeil said:

"Under the Road Vehicles (Construction and Use) Regulations (Regulations 61(7) and 61A(3)) and the Road Traffic Act 1988 (Section 42) it is an offence to use on a road a vehicle which has been modified in such a way that it no longer complies with the air pollutant emissions standards it was designed to meet."
https://www.gov.uk/government/publications/modifyi...
So it may pass the MOT with flying colours, but still be illegal.
Talk about confusing.

Hmmm - that's somewhat grey. As stated above, with secondary cats only removed the vehicle will still pass the UK emissions standards, which is was designed to meet, so I would see that it is still legal.

With the MOT standard it states it is a failure if you have modified them from the original design, regardless of if they pass emissions or not.

[BiggaJ]

AdamV12V said:

That is incorrect I am afraid. It will fail an MOT if you have removed or modified any of the original manufacture's emissions control equipment. See Section 8.2.1.1 of the MOT handbook.

https://www.gov.uk/guidance/mot-inspection-manual-...

As I put above however, it all depends on if your MOT tester knows what the original setup was supposed to be.

OK, I stand corrected thanks Adam however, how many test centres know of the OEM control equipment on a Aston? I bet not many and as my Indy has said, they dont have great experience of these types of cars and are often too afraid to meddle with them. I guess find a test centre you trust to just put the probe up the exhaust and it should pass.

[AdamV12V]

BiggaJ said:

OK, I stand corrected thanks Adam however, how many test centres know of the OEM control equipment on a Aston? I bet not many and as my Indy has said, they dont have great experience of these types of cars and are often too afraid to meddle with them. I guess find a test centre you trust to just put the probe up the exhaust and it should pass.

Indeed, I agree.

My car has the secondaries removed, yet it has passed the MOT twice, and it still meets the emissions standards. BUT it could fail in the future, hence I have the cats ready to be temporarily refitted for the test, should that occur.

[Felonious]

AdamV12V said:

BiggaJ said:

OK, I stand corrected thanks Adam however, how many test centres know of the OEM control equipment on a Aston? I bet not many and as my Indy has said, they dont have great experience of these types of cars and are often too afraid to meddle with them. I guess find a test centre you trust to just put the probe up the exhaust and it should pass.

Indeed, I agree.

My car has the secondaries removed, yet it has passed the MOT twice, and it still meets the emissions standards. BUT it could fail in the future, hence I have the cats ready to be temporarily refitted for the test, should that occur.

Ditto.

[raceboy]

Manners79 said:

I had the air intake upgrade done at the same time which also helps make the engine work a little more freely so I can't actually say for sure which bit of work resulted in which improvement, but it is not that simple anyway - it is more a 'sum of the whole' thing and for the difference in price (very little) it seemed logical to me to do the sports cats, remap and airboxes as one programme of work. There is then another stage which involves new exhaust headers but that is a step up in cost so I'll save that for the future.

I wouldn't want to pre-empt BR's pricing in public but suffice to say I was very happy with the price I paid, the quality of the work done and the results I got.

Tempted with this myself, curious as to a rough ball park....as mines a 4.3 anyway, price point, just to know how much sucking of teeth I'm likely to experience, and any idea on how long the work takes? Is a while you wait type thing, or a bit more involved?

[JonnyCJ]

LPH said:

Interesting comments - cheers

I was looking at a set of 'Harrison Signature' CATs from the USA. They seem to have a good reputation and apparently don't throw MIL lights....

A very detialled discussion / review here:

https://www.6speedonline.com/forums/aston-martin/3...

I fitted a pair of Harrison Signatures to my 4.7 last year during lockdown. Am getting it re-mapped as well, although I haven't had any CEL issues. Incidentally, if I ever switched back to standard, would I need to switch the map back for the standard cats ? Always wondered....