Catalytic converter

WorTortle · 2 Oct 2019 at 12:00

Just had confirmation from the indie garage, cat is in place and the exhaust has been fully replaced too.

Can't see why anyone would run a de-cat, it's just going to cause problems at some point.

Thanks for all the input and info

Flack88 · 2 Oct 2019 at 12:13

WorTortle said:
Just had confirmation from the indie garage, cat is in place and the exhaust has been fully replaced too.

Can't see why anyone would run a de-cat, it's just going to cause problems at some point.

Thanks for all the input and info

More power, less restrictions, better fuel economy, weight saving etc. A lot of higher power turbo cars would blow the inside of the cat straight out of the exhaust at high boost levels.

melchy · 2 Oct 2019 at 12:23

Has it been remapped as well? I'd suspect if its been running a decat there is a fair chance its been remapped as well. There is a chance that putting things back to stock may cause issues depending upon the map.

Flack88 · 2 Oct 2019 at 12:32

melchy said:
Has it been remapped as well? I'd suspect if its been running a decat there is a fair chance its been remapped as well. There is a chance that putting things back to stock may cause issues depending upon the map.

Very good point, may want to get the AFR checked.

Diagro · 2 Oct 2019 at 12:40

Take it to Ford and ask them to check? They can reflash if needed

WorTortle · 2 Oct 2019 at 13:11

That's my next port of call. It's definitely been remapped so I'm going to get it flashed back to standard. At the moment it's got too much power and it can't really handle it.

Just need to find the time to get it booked in.

Liquidfox · 2 Oct 2019 at 13:44

Praz94 said:
How do people get away with decatting their cars? I see so many decat cars at car meets, they sound incredible, but surely they must all know it fails MOT?

It sounds better and it accelerated harder due to less back pressure meaning boost came in a lot harder. MOT wasn't a worry as I had a "friendly" tester, as many will. The only issue you'd have would be if you were in a fault accident and couldn't swap it back out before the insurers got involved, or you had your car impounded by the police and they did a vehicle inspection (or in my case, the latter didn't matter as the copper was clearly blind).

Kei · 2 Oct 2019 at 15:52

Flack88 said:
Very good point, may want to get the AFR checked.

AFR, isn't going to be the problem. EGT is, but even then, it would only be an issue if driven particularly hard.

De-catting is illegal for any post 1992 car. That's why you replace the standard cat with a high flow sport/race 200 cell version if you want to gain performance. You get the benefits of the improved flow rate combined with the fact you know it'll pass an MOT and it is legal to drive on the public highway.

rodenal · 2 Oct 2019 at 16:49

WorTortle said:
That's my next port of call. It's definitely been remapped so I'm going to get it flashed back to standard. At the moment it's got too much power and it can't really handle it.

Just need to find the time to get it booked in.

Unless it's had a huge bump in power a remap alone isn't going to massively change the driving characteristics of the car. Find out what is already on it and whether there is any real issue running it without the decat (unlikely tbh) then save your money

Kei said:
AFR, isn't going to be the problem. EGT is, but even then, it would only be an issue if driven particularly hard.

De-catting is illegal for any post 1992 car. That's why you replace the standard cat with a high flow sport/race 200 cell version if you want to gain performance. You get the benefits of the improved flow rate combined with the fact you know it'll pass an MOT and it is legal to drive on the public highway.

Most 200cel cats are marked for Motorsport use only so they shouldn't really be on either - albeit if it passes emissions it's unlikely to be particularly scrutinised

Nasher · 2 Oct 2019 at 17:12

On modern cars removing the cat doesn't really gain a whole lot anyway. It'll make it louder and stink.

red eye · 2 Oct 2019 at 17:45

WorTortle said:
Is it weird if I just let that play in the background while I get on with the crafting?

No it’s not. I hum it at work when I’m bodging a tool, it gets the creative juices flowing

red eye · 2 Oct 2019 at 17:47

Praz94 said:
How do people get away with decatting their cars? I see so many decat cars at car meets, they sound incredible, but surely they must all know it fails MOT?

Unless of course its easy to remove and put back on, in which case I assume thats what they're doing

Cat on for mot then take it off. Or if they have a mot buddy that will hook another car up to the gas machine to log a pass

Akagi · 2 Oct 2019 at 17:48

Just buy the tester a packet of biscuits. My car doesn't have any cats on it.

red eye · 2 Oct 2019 at 17:52

Flack88 said:
Very good point, may want to get the AFR checked.

The afr is not set the ecu adjusts the afr using the o2 reading from post cat. Too much o2 and it will increase fuel it’s constantly being adjusted aiming for 14:1

red eye · 2 Oct 2019 at 17:53

rodenal said:
Most 200cel cats are marked for Motorsport use only so they shouldn't really be on either - albeit if it passes emissions it's unlikely to be particularly scrutinised

powerflow 200 cell are not marked.

Nasher · 2 Oct 2019 at 17:57

Just cover the underside in panels, then they can't physically check it

Flack88 · 2 Oct 2019 at 18:16

red eye said:
The afr is not set the ecu adjusts the afr using the o2 reading from post cat. Too much o2 and it will increase fuel it’s constantly being adjusted aiming for 14:1

Ahh right, never knew that. Used to old jap rotbox cars myself which run on windows 95

red eye · 2 Oct 2019 at 18:32

Flack88 said:
Ahh right, never knew that. Used to old jap rotbox cars myself which run on windows 95

It’s all to do with emissions but a plus is that most of the time the afr is at a word I cannot pronounce or spell lol 14 parts of air to 1 part of fuel, the golden ratio where there’s enough air to completely burn the fuel..... more power. Now the car makers need to concentrate on mass production n/a engines with 100bhp per liter.

Deleted member 209350 · 2 Oct 2019 at 19:05

red eye said:
Cat on for mot then take it off. Or if they have a mot buddy that will hook another car up to the gas machine to log a pass

I see. So is it easy to just take off and put back on then?

Nasher · 2 Oct 2019 at 19:29

It's not a hard job but would get annoying having to do it every year. Plus some cars will produce a CEL (which is also a fail), so you would have to re-tune the car every time.

Catalytic converter

Deleted member 209350

Deleted member 209350