Catalytic Converter

Technical queries, discussion and all-round enthusiasm for the Cappuccino.

Moderator: Steering Group

Catalytic Converter

Postby Collette Dobson » Wed Jun 26, 2019 16:42

Hi all,

What is the latest thinking on this and where best to get replacements? I have just had a warning light and the MOT tester said I need a new Cat and Sensor as it is reading sky high. However it isn't a fail because the car isn't on the system (!).

So although there is no panic I would like to replace them (or, looking at 10 year old forum notes, remove the Cat).

What are others doing?

Thanks

Collette
Collette Dobson
Regular Contributor
Regular Contributor
 
Posts: 26
Images: 2
Joined: Tue Jan 22, 2002 11:11
Location: Lewes, UK

Re: Catalytic Converter

Postby Ian Linden » Wed Jun 26, 2019 23:25

Hi Collette,

The sensor is actually a thermal fuse, see here for ordering from Amayama. I'm assuming you've already tried Suzuki GB? If not, try Levois

Unfortunately, they do not list the cat, Part No 14100-81811. This site may be able to help. They also give a price for14100-81812, which may be a direct replacement, and Amayama also list that part - not cheap (£484 plus VAT and customs clearance).

The reason your car is not on the system may be the one given here, as your car is M reg., and Ls and Ms are exempt the cat test.

EDIT: That being the case, if the car is running well. i.e. the cat is not restricting the exhaust, you could just leave it. It should be possible to extinguish the lamp by earthing the thermo fuse connecting wire or just disconnecting and insulating the connector if it works the other way :D
SCORE Treasurer & Membership Secretary
User avatar
Ian Linden
Steering Group
Steering Group
 
Posts: 4022
Images: 10
Joined: Fri Jan 18, 2002 21:58
Location: St Lawrence, Jersey, Channel Islands

Re: Catalytic Converter

Postby Murray Betts » Thu Jun 27, 2019 21:19

There is an overheat sensor after the cat, as Ian says, but that is a fault detector item (indicates catalyst overheat due to misfire etc). It's an early version of self-diagnostics. Of itself it doesn't actually regulate or control the basic fuelling.

There is also a conventional lambda sensor before the cat which provides the feedback for fuelling control. It sounds like something is faulty in your system and you could do with getting to the bottom of it really.

If the engine is firing properly on all 3 cylinders it's a good start. Simple way is to check all the spark plugs look OK, and ideally do a compression check. It could be something as simple as a faulty HT lead or cap or plug, or rotor arm etc. causing a misfire.

After that you need to determine whether the lambda sensor output is fixed high or low, or is cycling (as it should).

I'm guessing the exhaust emissions for HC and CO are way too high? In that case the lambda sensor would probably be giving high voltage (something like 1.0V typically) and "clamped" (i.e. not cycling). If it is cycling hi/lo then even if the cat has deteriorated the HC/CO probably wouldn't be sky high, unless it is completely de-activated for some reason. If it has a misfire the lambda sensor may well be reading low (zero) due to having oxygen from the misfiring cylinder in the exhaust, but HC would be sky high from the unburnt fuel and if the feedback was still trying to richen the mixture in response to the free oxygen then that would make matters even worse in the other cylinders, and HC/CO would increase more.

It could be running too rich if it thinks the temperatures are too low, for example, coolant and/or air temps. Or there could be a leak or split in the small hose to the MAP sensor for example, this would make the ECU think it was running higher load than it really is at idle and would be adding too much fuel. The sensors themselves could be faulty.

If you can find out whether the engine is actually running correctly but just the cat performance has deteriorated then in your case it probably won't really matter much, and as long as the monolith inside hasn't collapsed and potentially blocked the pipe then no big problem. If the engine isn't running correctly it needs to be resolved.
Murray Betts
Message Board Guru
Message Board Guru
 
Posts: 1183
Joined: Fri Jan 18, 2002 20:20
Location: Warwickshire, UK

Re: Catalytic Converter

Postby Collette Dobson » Mon Jul 01, 2019 16:04

Thanks for all the info. Not sure I want to invest £500++ given that the tester obviously knows the rules and didn't test it against a CAT spec.

Some old posts suggest it is OK to just take the cat out of the housing - has anyone done that? I am thinking you could then get the engine tuned in that configuration.
Would a new Lamba sensor be a good idea anyway?
Collette Dobson
Regular Contributor
Regular Contributor
 
Posts: 26
Images: 2
Joined: Tue Jan 22, 2002 11:11
Location: Lewes, UK

Re: Catalytic Converter

Postby Ian Linden » Mon Jul 01, 2019 17:22

Just emptying the housing would upset the gas flow through it, but I don't see why you should not just insert a length of (say stainless steel) pipe through the monolith to forestall a subsequent collapse, assuming the gas flow through it is a straight run.

Afaik, retuning the engine would involve crafting bespoke software for the ECU, using a rolling road test setup - a very expensive business (making £500 look cheap), especially as it is unlikely that the car tuners currently practicing would have any experience of the Cappo's ECU.

As the car has passed its MOT, I don't see that it needs a new lambda sensor. I think the reference to a sensor in your first post is sowing confusion - I think that thing is a thermal fuse to announce that the cat is overheating, not a lambda sensor (I'm assuming that the fault lamp you see is caused by the thermal fuse, but if that is not the case, Murray's advice should be followed).
SCORE Treasurer & Membership Secretary
User avatar
Ian Linden
Steering Group
Steering Group
 
Posts: 4022
Images: 10
Joined: Fri Jan 18, 2002 21:58
Location: St Lawrence, Jersey, Channel Islands

Re: Catalytic Converter

Postby Collette Dobson » Mon Nov 04, 2019 11:16

Returning to this topic after a while. The part number Ian provided seems to be for the cover. The parts picture doesn't show anything inside the cylindrical container, but I am assuming there must be some sort of cartridge inside - the actual converter. If I am right, does anyone know the part number for that?
Thanks

322
Collette Dobson
Regular Contributor
Regular Contributor
 
Posts: 26
Images: 2
Joined: Tue Jan 22, 2002 11:11
Location: Lewes, UK

Re: Catalytic Converter

Postby Ian Linden » Mon Nov 04, 2019 13:28

Item 21 is described as "CASE ASSEMBLY, catalyst". That means it comprises more than one part, and I have been told (years ago) that it includes the actual converter. Also, I don't think that even Japanese spare part prices would stretch to £500 for an empty case :D

Also, exhaust pipe No2 (the rear pipe section) is described in the manual as containing a catalyst. I think it safe to say that the actual converter element is included in the case and pipe, respectively.
SCORE Treasurer & Membership Secretary
User avatar
Ian Linden
Steering Group
Steering Group
 
Posts: 4022
Images: 10
Joined: Fri Jan 18, 2002 21:58
Location: St Lawrence, Jersey, Channel Islands

Re: Catalytic Converter

Postby Collette Dobson » Tue Nov 05, 2019 11:44

Thanks for that. I have not taken ours off, so I don;t know what it looks like inside the container. I am wondering if one could modify something like this
https://www.louis-moto.co.uk/artikel/ak ... escription
if it was a suitable size.
Collette Dobson
Regular Contributor
Regular Contributor
 
Posts: 26
Images: 2
Joined: Tue Jan 22, 2002 11:11
Location: Lewes, UK

Re: Catalytic Converter

Postby Ian Linden » Wed Nov 06, 2019 00:41

As you are M reg., you don't need a cat, so why bother? If the car runs ok in it's present condition, just kill the fault lamp and drive on. If the cat is, or becomes blocked, I still think what I suggested in my 2nd post in this thread is the best solution
SCORE Treasurer & Membership Secretary
User avatar
Ian Linden
Steering Group
Steering Group
 
Posts: 4022
Images: 10
Joined: Fri Jan 18, 2002 21:58
Location: St Lawrence, Jersey, Channel Islands

Re: Catalytic Converter

Postby Collette Dobson » Wed Nov 06, 2019 13:14

You are probably right and I could just be creating a big job. Always seems a shame to not have something working like it should though.

As the car is running fine it is probably all down to when I get around to taking the thing apart - which could well be months away!
Collette Dobson
Regular Contributor
Regular Contributor
 
Posts: 26
Images: 2
Joined: Tue Jan 22, 2002 11:11
Location: Lewes, UK


Return to General

Who is online

Users browsing this forum: No registered users and 0 guests