I thought i might chime in here and help as it might help someone deciding which way to go regarding engine management systems.
I have some time and i have read some posts touching in this area.
As you all know by now i have been doing years of research on how to add a turbo to a 205 with factory reliability and keeping it legal.
I mean by law (Engineering certificate)
And epa legal (Enviroment protection agency)
Now the easyway is turf the analog L jetronic or the series2 motronic and replace it with a decent computer Haltech,Autronic,Motec prices vary from $1500-$2700 for the big three and you certainly get what u pay for when it comes to price for engine management systems.
The problem is once u replace anything (That includes throwing the famous airflow meter where it belongs in the trash can)You r no longer epa legal.
Now even though you will most likely be running much cleaner or about the same say with (Bigger injectors in you engine)It will not be worth a cent as you will need to take the same route peugeot had taken to comply with the law(Very very expensive to say the least)
Now in my opinion the Lu2 jetronic thats in the s1 gti is very reliable.
If you willing to take a risk and replace your computer (It's you car)
I don't think it is really worth changing your oem system if you r making under 160hp and not many 205's r making those sort of numbers in oz (Standard computer with the correct injectors is good for around that figure)
As you all know buy now i have been doing research and devolopment on a turbo kit for the little 205 for years and it does take years to build a kit that will be legal by law and not sacrifice factory reliability (Anyway i will be in the driving and testing phase this month)
It will be the only turbokit of it's kind in the world for a peugeot car.
The only other kit has come from turbo technics and that only used a single xtra injector and cast manifolds.
I will let you know what way i have gone after much head scraching.
I will be using a auxillary fuel computer running a xtra 4 injectors in the oem inlet manifold (I am using 4 injectors to have perfect fuel distrubution and they will be mapped according to the engine requirement so nothing will be changed where they test for emitions so therefore will be epa legal.
The factory ignition timing will be controlled by the computer and be retarded when in boost conditions.
I hope some of this helps someone (But i have come to the conclusion after much head scraching)
In melbourne you might not even pass a roadworthy without the air flow meter (Once i would not care but now i feel much better cruising downtown into melbourne with my turbo 205 knowing i will not get a canary slapped on my window like the ginos in there commondores at chapel st hanging burnouts for attention.


Take it easy