Euro 4 cats

[kyleb]

The exhaust I used was an old Robnell exhaust from the 90s. I am told by a reliable source that Ford used to use much better quality cats back then due to the poor emissions of the engines. Now the engines are much better with emissions due to the fuel injection and computer setup means they don't have to be so stringent.
I will find out what sort of a temp rise you should expect, just bear in mind a cat acts like a blowtorch just completing inefficient combustion. So you will see an appreciable rise.
I think if whatever cat you use lights off properly you will be fine.
Its more the tune and positioning of your MAF which seems to have more of an effect on Emissions than anything. I am told 400mm from throttle body is ideal to give the computer time to respond, with that being said mine passed, (albeit only just) with it about 100mm from the throttle body.

[Rebel1]

I have a friend who is a Manager at one of the Major mine sites. Part of his duties is managing the emissions of Gasoline Engines in enclosed conditions.

He swears by adding a little acetone to ULP. He says they use it in
very small amounts in all engines on the site. He also claims that their on-site procedure manuals insist on the acetone be added to their bulk fuel tanks at the time of delivery of the bulk fuel.

It is even added to their diesel fuel at the time of delivery.

ie. For every 5000Ltrs of fuel delivered they add X amount of acetone.

So I took his suggestion and googled it and came up with the following:
Acetone In Fuel Said to Increase Mileage

This cut n Paste from that site is interesting:

Acetone can reduce hydrocarbon emissions up to 60 percent. In some older cars, the HC readings with acetone in a 1986 GMC went from 440 PPM to 195, as just one example. Though mileage gains taper off with too much acetone, hydrocarbon emissions are nevertheless greatly reduced.

Just thought I'd throw it in here. Try at your own peril as I've certainly not done any tests.