[b3lha]

I remember reading, a long time ago, that SVXes sold in California were detuned from 230hp to 220hp because of the stricter emissions regulations. I can't find a reference to that anywhere, and the numbers are a bit too rounded to be believable.

However, from looking at the 1992 USDM factory service manual, it does seem that the California model has a different EGR system. If you look at the attachments you can see an "EGR Temperature Sensor (California Only)".

Looking through the ECU program, I can see that it has two modes. Standard mode and California mode. It uses different numbers in some of its calculations depending on what mode it is in. There are so many unknown variables that I can't say what effect these values have on the performance of the engine. It seems possible that the ECU might tradeoff some performance for better emissions.

The ECU decides which mode to use depending on pin 4 of connector B62. If this pin is connected to ground it will run in California mode, otherwise Standard mode. If you have a California SVX, you could maybe reclaim a couple of hp by cutting or adding a switch in this wire.

If anybody wants to experiment with this then I suggest the following experiment:
1) Verify that your car is a california model (does it have an EGR temp sensor?)
2) Unplug the sensor and run the engine, check that you get a CEL code 55.
3) Plug in the sensor, clear the code and check it is clear.
4) Disconnect the wire from pin 4 of connector B62.
5) Repeat step 2. This time you should NOT get CEL code 55.
6) See whether there is any measurable difference in performance.

See attachments.

Phil.