O2 sensor on Row's

[oldschoollear]

I read recently that euro cars did not come with the o2 sensor. Is this true? My 1985 row has a cat and the o2 sensor installed. What would be the possible outcomes of removing the o2 sensor?

[javadog]

Cats were optional on 911s in Europe, once the green movement reared its head. Those cars equipped with cats also had O2 sensors. I wouldn't remove the sensor. No point, really. Consult the other two threads on this page, on related topics, for more details about how the system works.

JR

[livi]

As JR said.

We European dirt bags need neither cat nor O2 sensor. They could be ordered with a cat with a reduced tax premium in Germany. However they were then quoted 217 bhp instead of the regular 231. I think most originally equipped with a cat have since been removed. Why miss 14 bhp?

[oldschoollear]

So the cat "robbed" the car of 14 horses? This maybe my next project

[livi]

I am skeptical personally, but that is what they claimed. Not sure I would feel the difference anyway. However, it is easier to adjust exhaust valves without it.

[oldschoollear]

Ok , I have been going through some old mags. It seems that for the 1985 model year(euro) that the cat was an option. As was a lower compression, 207 hp engine (this sounds like the US motor, am I reading this wrong?). I was under the impression all euros were of the 231 hp variety, can anyone elaborate?

[livi]

All standard euro 3.2 84-89 had 231 bhp and the same compression. Yes, I think you are referring to the US export cars.

[javadog]

No, no, no. When unleaded fuel was introduced to Europe, the octane rating was lower than leaded fuel. The optional cat-equipped engines (930/25) had a lower compression ratio and different DME control units, to accomodate the reduced octane levels. The power was either 207 or 217 hp for the 930/25 engine, depending upon which market it was sold in. Most were 217hp.

JR

[Bill Verburg]

For My 84-85 there were only 2 n/a engine types
930/20 no cat 231 hp, RoW
930/21 w/ cat 207 hp, US/J

For MY 86 there were 3
930/20 no cat 231 hp, RoW
930/21 w/ cat 207 hp, US/J
930/26 w/cat 231 hp, Switz/Swed/Australia

For MY 87-89 there were 4 engine types
930/20 no cat 231hp, RoW
930/25 w/cat 217hp US/Austria/Switz./J/FRG
930/25 w/cat & modified DME 207, Australia
930/26 w/cat 231 hp, Swed.

[oldschoollear]

Sorry for the long wait. I have the 930/20 motor(finally found the code!) with a cat. Am I really missing anything with the cat installed? And from a different angle, does the cat effect the sound of the exhaust note compared to a test pipe? Thanks

[Dave (Oz)]

With that engine model code you should have engine number 65Fxxxxx (for '85). The same engine model number 930/20 covered all ROW engines from '84-'89, delivered with or without cat to various markets to meet changing loacal regs. ALL are quoted as 231bhp by Porsche, but logic dictates that even with changes to the EFI system to compensate, something must be lost in adding the cat. But Porsche were pretty conservative with bhp figures, so maybe there was enough overhead to cope with addition of the cat? We need someone who has dyno'd before and after removing the cat to weigh in here with objective data...

[wolf]

930/26 is w/airpump, no cat.

[Steve W]

When, ROW Carreras (930/20) were brought into the U.S, for proper federalization, they needed cats and O2 sensors installed. There are a lot of 84-85s that were improperly done by just installing a cat and fitting a O2 sensor in that was not connected to anything. Some used a hokey aftermarket piggyback box for the O2 sensor that altered the sensors to the DME to lean it out. Others changed out the Euro chip and installed a copy of the U.S. chip. Some others also opened up the air flow meter and tightened the spring tension in the flow meter to lean it out.

The proper way to do this is to this is to change out the Euro DME for a U.S. DME that has the additional circuitry to recognize an O2 sensor (or modify a ROW DME with the appropriate caps and resistors and change the chip to a U.S. version), along with installing a cat. The only difference between a U.S. DME for 84-86 (0.261.200.050) and a ROW (0.261.200.051) is the additional circuitry for the sensor. Most of the later ROW cars (86 up) that were imported were done this way probably due to stricter enforcement. That said, there are a lot of 84-86 ROW cars still running around the U.S. with the original ROW DME.

Some of the earlier improperly done grey market conversions were redone properly later in life per the above method. Others where the owner still has the original ROW DME and resides in a state without emissions tests, just removes the cat and O2 sensor entirely. The difference with and without a cat is basically just about 6-7 hp at the very upper end of the RPM band >5500.

Also, a 930/26 is basically just a 930/20 with an air pump.