daibutsu

Can or has anyone used a Federal emission ECM on s Cali Emmissions car, will it work,or No?

mattscar

Ive been researching this and unfortunately it will not work due to the California having an extra o2 sensor.

logix7

mine is cali with 3 oxygen sensors. which is the "extra" ?

Ali SC3

iTrader: (10)

Probably the third one after the cat.

mattscar

joe diego

iTrader: (3)

throw in an Aristo ECU... Viola

Don't forget the map sensor, COP, IAT, toyota igniter...

KahnBB6

iTrader: (5)

^^ Ali is right

It wasn't until 1996 OBD2 models that all SC300's got the 3rd O2 sensor. Prior to that it was only 1992-1995 Cali-Spec Emissions SC300's.

If you have a California 1992-1994 SC300 and you run a Federal 1992-1994 SC300 ECU the car will run but you will have a CEL light because of the presence of the 3rd O2 sensor underneath the car, although that 3rd O2 is only there to check the efficiency of the 2nd catalytic convertor. I'm not entirely certain but there shouldn't be any other issues such as running rich due to that CEL.

Now what you should NOT do is run a 1995 or higher Federal or Cali SC300 ECU in a 1992-1994 SC300. Doing so will cause the car to run very rich because that ECU is expecting heated O2 sensors to be present and will run rich to overcompensate. This will cause you to prematurely wear out a perfectly good #1 and #2 cat not to mention your spark plugs.

Unless you're planning on an extensive NA-T build using an Aristo GTE ECU along with other supporting modifications it is best to find the right year/range Cali-Spec SC300 ECU for a Cali-Spec SC300 with that extra O2 sensor wiring.

Consult this list of verified SC300/400 ECU part numbers to be sure of the one(s) compatible with your car in its stock configuration:

https://www.clublexus.com/forums/per...s-by-year.html

Bdub215

iTrader: (1)

The solution to run a fed ecu in a Cali car is depin the 3rd o2 sensor. Both the Signal wire and heater wire.

Done.

KahnBB6

iTrader: (5)

If you no longer have to concern yourself with emissions testing in PA then that will work but not in CA with a Cali-Spec emissions SC300 chassis when test time comes around-- reason being that it isn't so much that the Federal ECU would be made happy by de-pinning the 2nd O2 sensor that it does not know exists anyway but how that Cali Emissions car is expected to perform for that year by the BAR once it goes on the dyno. Programming for the chassis matching model year and trans Cali ECU likely differs slightly from Federal variant for the same year.

But if someone isn't in California, unless emissions in their county still requires a full roller dyno smog test every two years it would not be an issue.

All the non-turbo 2JZ-GE emission systems for the Supra MKIV NA, SC300 and GS300 got differing year-by-year updates basically until the 1998 2JZ-GE VVT-i's standardized much more of that hardware across the board. During the early-mid 90'she new emission requirements from CA were actively being phased in at the same time Federal OBD2 emissions were on the horizon and Toyota/Lexus seemed to add specific updated emissions equipment piecemeal only as-needed every year or every other year.

1995 Cali-Spec SC300's have to be the weirdest because Cali required some equipment present on OBD2 cars a year earlier than 1996 Federal SC300's got them. The 3rd O2 sensor on the #2 cat is the only consistent Cali-Spec difference from OBD1 Federal cars/ECUs from 1992-1995.