ok so where is this EGR system that is supposedly on the zetecs, if its not the air injection into the manifold then where is it, cz ill be dammed if ive seen one on a silver top zetec!
the reason i said about the emissions is because that is what i was told by one of our master techs who was previously a master tech at ford when the rs1800 fiesta was available, warming up of the cats will also effect emissions so im thinking its most likely both rather than to be just to warm up the cats as the percentage of harmfull gases will be lowerd if the amount of exhaust passing through the system is increased. however the rs2000 owners club website contradicts this saying like you said it is meerly to aid in heating up the cats so i shall be querying him again about this tomorrow.
i know egr valves are designed to lower the combustion temperature but what people are refering to on here is not an egr system, it is a pulsed air injection system into the manifold so it makes it irrelevant to the discussion surely?
the system in which people are refering to as EGR is this system marked 2 correct? (this is an rs2000 manifold but just imagine a zetec cast manifold rather than a tubed 4 branch)

if this is the case this is NOT an EGR system.
Dirtect quote from rs2000-16v.com
Exhaust Air Pulse System removal
Guide by Gavin Dent
The exhaust manifold on the rs2000 16v escorts is well known for being restrictive. The reasons for this are partly to do with the construction method of it and also due to the air pulse System (APS). This system is also incorrectly known as the EGR (exhaust gas recycling) system, which it is not, that is a completely different type of system.
The APS's job is solely to speed up the heating of the Catalyst in order for it to work efficiently, that's all.
This system is only used on the warm up cycle and it does not affect the emissions come MOT time as this reading should be done when the car is at working temperature. Due to this fact many rs2k owners remove this system. First you need to remove the manifold.
We will start with the APS and below is a diagram and a list of parts:
1) Manifold
2) Pulse air tubes
3) Pulse air valves
4) Air control system
5) Pulse air filter
6) Lambda/hego sensors x2.
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rs2k powerd escort mk4.....figured id be different!
http://WWW.S2RS.CO.UK