Hi MB friends

Thank's for the membership, I'm new here and after an exhaustive search this is one of the best and informative club.

I own an 124 300E 1987 with only 65K miles forgotten in a farm garage. and the last 2 months, despite the dust, the car is really in a goood shape.
It's a MB USA version, I'm still trying to figure out how it landed here in Chile, where al MB's are Euro series.
This means that the car has a Cat and here the Cats by law started in 1993.
the gasoline octane here is roz 93, 95, and 98

So, the first move was to remove the cat and the pre cat, because
a 1987 car don't need it and the emission control for a car without
cat allow 1.5% CO and with cat only 0.5.

Having the cat removed, I noticed a power increase but it was not so much I expected, so I started to search...... there was no
distribuitor to advance, no carburator to adjust....finally I found the two RESISTORS R16 and the infamous R17 .

The R16 (catezl) was 750 Ohm , I pulled it out for 95 Octane and no retard.
The R17, located behind the batery, was a 0 Ohm .
This resistor seems to be a tabu item, nobody know or want to talk about, and it is perhaps more important and efective than the R16. I think it controls the amount of fuel inyection and switch the use of a lambda sensor or to the intern KE inyection manager.
the 124 inyection was made for both systems, with or without cat.

Well, I said before there was a 0 ohm resistoe in and Changed it step by step increasing 500 Ohm, and the best result was without resistor.
The engine run soft and smart, and acelerate like a sl model.
The fuel consumption range between 23-25m/g and I hope the CO emission keeps in range. at least the exhaust remains braun after highway drive.

I really think a 123 with cat also can gain some improvement removing the R17, but I'm not an expert and maybe the real experts here would add some comments about.
Any comments or ideas are welcome

Gerhard

My 190E 2.3 also has that resistor, I think.
It has a EZL resistor marked "S" and "N", I suppose that's R16, is connected to the ignition controller and perhaps it controls the ignition timing.
BUT behind the battery, connected to the fuel ECU, there is another similar knob, with pos. marked from "1" to "7". It is currently in pos "1". Is that R17? I suppose so.
Does anyone have official information on this resistor?
My Vivid Workshop CD says it control the mixture, and that the default pos. is "1", nothing more.

Thanks!

has anyone tried to mess with the r17/1 on the 300SE? according to alldata, its located on the right side of component compartment, by the battery I suppose, but I am unable to find it. however, there is a R17 trimming plug, located somewhere near the ECU, which I was also unable to find, does this one have the same function as the r17/1? If you have some pics, that would really hit the spot. I have already removed the R16/1 and I like the results, especially above 3k rpm.

nenad

anyone has a picture of a r17 from any vehicle?

nenad