Cat back or decat?

[Grey One]

Hi Guys

I need to replace my old exhaust as it is a bit knackered on the ISF.  Looking at Hayward & Scott X pipe options they do a catback and decat option, for 'roughly' the same money.

Question: are there any advantages to decat, does it add to the insurance cost, or need technical work on the plug-in sensors, better to stick to decat?

Any thoughts/experiences of this appreciated.

Thanks

[scudney]

If you want to remain legal then cat back is the way to go,if you go decat your car will fail its emissions,which will then require the cats be fitted in order to pass its emissions test 

[Cactus]

@scudney It will still pass mot. 
@Grey One if you want more power down the line then go for decat.  

[NemesisUK]

It might well pass on emissions but if the tester checks the database he'll see the car has been modified and to modify any emissions related items is a fail.

[scudney]

Lol I won't argue but its a fail,if car is fitted with a cat it has to pass with a cat, might do with a bent mot tester though 🤣🙃😄

[Grey One]

31 minutes ago, Cactus said:

@scudney It will still pass mot. 
@Grey One if you want more power down the line then go for decat.  

Cheers Guys - catback it is for me 🙂

[ColinBarber]

4 minutes ago, scudney said:

Lol I won't argue but its a fail,if car is fitted with a cat it has to pass with a cat, might do with a bent mot tester though 🤣🙃😄

The car still retains its primary cats and would pass and MOT if the engine is hot, which it should be anyway. The secondaries are replaced with silencers so it would be impossible for a tester to know if they were cats or not so the MOT isn't an issue.

It potentially is still illegal though:

Quote

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.

Unless you put the modified vehicle through the Euro emissions testing and it still came out in the same category then you won't know if you have altered it in such as way that is no longer complies.

[Therickster]

Hi as above,H&S only deletes secondary cats and replaces with silencers, no modifications needed to sensors etc no mil lights ,tested my emissions after fitting and hardly any change, flew through mot no advisory’s 

[Grey One]

That’s good to know, the idea of a clean new exhaust is very tempting.  Is the sound louder/different to a cat back does anyone know?

thanks 

[mr_s81]

On 7/7/2021 at 7:56 AM, Grey One said:

That’s good to know, the idea of a clean new exhaust is very tempting.  Is the sound louder/different to a cat back does anyone know?

thanks 

I'd be interested to know this too.

[TTE]

Same here,  cant decide between the two

[Grey One]

So a quick update on my original post above, I ordered and have had fitted a new H&S cat back X-pipe exhaust and the difference is night and day over the old one, just wish I had done this before.  The exhaust the car came with was also H&S but was just 'wrong' - it was probably an early one and may have been a dud, or got second hand a bit bashed about and fitted to the car, but certainly it had been installed badly and was blowing from the joints where the different parts were connected.  Like I say the other one was just crap, so glad it has restored by confidence in H&S exhausts.  Anyway, now with a properly connected and sealed exhaust, the wonderful melodic feel base sound the car omits is fantastic, so glad I had this done!   😀

[scudney]

Good for you and well done 👍

[TTE]

So to be clear you got the catback, not the full system? Any soundclips?🙂

[Grey One]

Yes, I got the cat back, didn’t want to mess with regs etc getting a cat delete, I’m sure it’s fine, but happy with what I got 👍🏻

[TTE]

Thats good to hear🙂 I am also thinking about getting the cat back system, would you say it sounds like this:

 

[Grey One]

Yes, I'd say so 🙂

[TTE]

Nice😎

[mr_s81]

On 8/14/2021 at 12:15 PM, Grey One said:

 

So a quick update on my original post above, I ordered and have had fitted a new H&S cat back X-pipe exhaust and the difference is night and day over the old one, just wish I had done this before.  The exhaust the car came with was also H&S but was just 'wrong' - it was probably an early one and may have been a dud, or got second hand a bit bashed about and fitted to the car, but certainly it had been installed badly and was blowing from the joints where the different parts were connected.  Like I say the other one was just crap, so glad it has restored by confidence in H&S exhausts.  Anyway, now with a properly connected and sealed exhaust, the wonderful melodic feel base sound the car omits is fantastic, so glad I had this done!   😀

Pleased to hear that @Grey One. Like yourself I have also bit the bullet and ordered a cat back system. I went for the non x pipe version on the advice of H&S, so I'm hoping I'll be as pleased with the results as you are!

I opted to keep the 'fake' exhausts. Mainly because I don't mind the look of them and secondly due to the fact that they (apparently) provide some function in terms of aero. I've no idea if that's true or not.

Either way, I'm looking forward to unleashing the v8 sound. Unfortunately it's a 6 week wait, so I've another 4 to go!

[Grey One]

Curious on what basis they recommended a non-X pipe, did you ask for the quietest option?

[dman2004]

On 8/17/2021 at 10:20 AM, Grey One said:

Curious on what basis they recommended a non-X pipe, did you ask for the quietest option?

The H pipe is a lot louder/bass-ier.

[Grey One]

Interesting, well please let us know how it goes, I’m sure you’ll be pleased with the difference 👍🏻

[mr_s81]

On 8/17/2021 at 10:20 AM, Grey One said:

Curious on what basis they recommended a non-X pipe, did you ask for the quietest option?

My initial idea was to go with the x pipe version as they still sounded great in video clips. I made it clear that I wanted to avoid drone and they said drone is only an issue if the secondary cats have been removed. Given I was going for the cat back only, this was not an issue.

As long as it isn't loud while cruising along, light acceleration etc, I won't mind.