No oxygen sensor !!!

[Ali]

Car : BMW 525i 1993 manual gear, M50 without Vanos.

I've been getting very poor fuel economy (compared to every other car I've owned upto this one) I filled up a full tank 5 days ago I assume it's close to 17 gallons cause I paid 81 Dirhams (local currency here Dirham:USD = 3.75:1, and petrol is approx. 4.95/gallon) and it gave me a total of 382 kilometers on it thats 4.7 kms/litre, the worst car I've driven previously was a friends 1988 500SEL which gave me about 6 kms/litre which I thought was ok considering it's a very heavy 8 cylinder vehicle with an prehistorical type of fuel injection (CIS), my 1994 V6 Camry (owned only for 2 months) normally came close to 9-10kms/litre, is this figure normal or could it be something is wrong with this car, I've changed plugs, oil+filter, fuel filter, exhaust with one from a 1989 750i from the second muffler to the exhaust tip (old one was leaking in too many places and when taken out and shaken sounded like full of carbon or something ???) also ran injector cleaner through the tank 3 times, fuel consumption is the only concern here otherwise idle is smooth, I could be wrong and this kind of figure could be normal for this car (time to start thinking about a 1995-96 318i ?)

One more thing related or not I don't really know, I think a "stomp" test (I've been reading about these a lot over here) does not work on my car it does check the speedo and tacho guage and give some figures in german including last 7 characters of my Chassis No i.e. BG50725 and some fuel index but no codes, my car does not have an obc just a normal analogue clock, also all cars here (until the last 4-5 years) didn't come normally with a cat unless u specified it, I know for sure mine doesn't have one and maybe not even a oxygen sensor (don't know where else to look in the absence of a cat). Would the absence of this give me a bad fuel economy wouldn't it throw some sort of an error code even without an obc, also is it very difficult to do the complete wiring to install (one what does it connect to) if it is not there without screwing up somewhere.

Also my car on exceeding 120kmph gives an message of "speed limit on the dash can I do something to make this come on at a higher speed like 160kmph for example or ending it for good.


Ali