[Diy_efi] ECU/engine designed for O2 running without

[Bill Washington]

Our Peugeot 505GTI waggon (2.2litre, NA 4 cyl delivering about 120 HP 
when new)with LE2 Jetronic .... Yes I know! Ancient Analog Injection......
had the wires ripped out of the O2 sensor when we bought the car - at 
that point the car had done 314,000 km, and the the O2 sensor had been 
disconnected for an indeterminate time - having been a farmer's car the 
sensor wires were probably ripped off on a obstruction years 
before......and not replaced.
The head was removed at that point to fix oil leaks from the head 
gasket, and the original honing marks were still visible in the bores!!!
    We did another 10,000 km before replacing the O2 sensor, suffering 
about 10% increased fuel consumption running open loop.....after about a 
further 50,000km that O2 sensor died for indeterminate reasons, about 
the time we headed off on an 8,000km trip (Melbourne -Townsville return) 
- O2 sensor failure was diagnosed and replaced about 4,000km into the 
trip...... the car has now done about 430,000km, still running sweetly, 
albeit with a little blowby.....still great to drive, no significant 
amounts of oil used..... about 1.5 litres in 7500km, pulls well, 
accelerates as well as can be expected for a big car with a small engine.

I conclude, as has been stated by a number of people, that the 
consequences of running open loop in a vehicle designed to run closed 
loop is largely vehicle/ECU/engine configuration/for a digital ECU base 
map accuracy/and even perhaps driving style dependant........the Peugeot 
engine has survived quite well....but then again Peugeot engines for 
surviving significant abuse with minimal damage, so perhaps I shouldn't 
be surprised ...and I know that not all engines are as robust and 
forgiving.....

Bill
(returning to lurk mode)

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