Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing De Catting

Does anyone know if I can legally remove the cat from my 1992 Ford 1.6 CVH engined 4/4 ? First Registered10.08.92. Kreg
I believe the regs changed that year
Thanks
Col

Looking into this a bit further I conclude it is not a sensible thing to do as the engine mapping could be affected I seem to have just one lamba sensor infront of the cat.

That would have no effect if the cat is removed. It is the second sensor after the cat that would have an effect (if one was used). Basically the second sensor is there to control if the cat is working. The first sensor, pre cat, in your case the only sensor, is to control fuel mix.

Col,

My understanding is that cars made after August 1992 had to be supplied Cat fitted, but you could register a catless car built before August up until Jan 1993 first registration.

So, if your car was built by Morgan after 31 July 1992 it had to have a cat fitted, but you don't need to have one in the car at that registration date. So I think you could remove the cat, but you WILL need a map for a cat less engine.

Peter, I would be surprised if a remap was necessary. I have had quite some experience with de-catting motorcycles and, whilst a re-map will generally get something more out of the engine it is not necessary as the sonda lambda sensor controls the mixture and the ecu makes the necessary adjustments.

Peter,

you are right on open systems: but cats need to run rich to burn the CO and NOx. So with no cat the mix can be leaner, better economy.....often the lambda probe can't achieve this.

On closed loop systems with a pre and post cat probe I understand a full new map is needed so that the ECU doesn't look for any lambda probe readings.

Why do you want to remove? You will not gain much power increase, 2-4bhp if your lucky. If its for a better sound then I think there are sports cats out there, or replace the silencer box with a sports one, which will probably give a better result. You will probably need to remap the ECU if remove the cat.

Thanks for your input so far; my Mog has a loud exhaust which drones and being an old fart I find it tiring when driving; so I am considering a quieter system to make the car more enjoyable to use, and it has been suggested by the exhaust fabricator I could remove the cat.

So I assume a quieter system could use a few Hp, but this could be balanced out by removing the cat? But then again I dont think I would notice the performance difference, so it could be totally irrelevant.

Hmm! I think you have been given some bad advice. A cat is very expensive and the exhaust guy you have been to may be trying to avoid the expense, or at least trying to win your work with a cheap price. Removing the cat, if you are not looking for more power but looking for a quieter sound, is a bad move. The cat also acts as part of the silencer system. If you don't like the sound it may be that the exhaust has already been changed for something non standard.

I would suggest you may be better off talking to a Morgan dealer and getting him to check your system and tell him what you want to achieve.

Peter,

I agree 100%!

There is a specialist exhaust manufacturer in Salisbury who makes 100% stainless systems, including high flow cats: the cat is about 50% of the cost....
When you talk to him he always asks if you want the system to sound "as the original", or loud.
But as Morgan systems are stainless anyway and based on the cats on my Roadster seem to use expensive high flow units going back to stock would seem to make much sense.