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Discussion Starter · #1 ·
As probably some of you know, California is now checking the ECU identification, so it is not possible to pass smog with a 2zz engine just making it look like a 1zz.

I have been thinking whether it would be possible to use the original ECU to control the 2zz enough to do all the checks and pass smog.
The idea is only to pass smog, so max RPMs and lift don't need to work.

Alternatively, one could use the 2zz ECU (or other system) as a piggyback.
So that the SMOG station talks to the 1zz ECU but the engine is really controlled by another ECU.

Any one has some idea about this?
I know the SMT people has done something similar.

Any resources that you might know about this are welcome.
 

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If you use 1ZZ and 2ZZ ECU's simultaneous, I don't thing that's possible. But if yes, they will fight each other.
1ZZ ECU itself will no match with 2ZZ camshaft degrees's. Maybe It will run but not proprely/enoughtly to pass emission test's.
 

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To run 2zz with a 1zz ECU and not generate any DTC.

Reverse the engine harness changes of the swap. If you are using a MWR swap harness this would be easy, just remove the swap harness and plug the engine harness directly into the 1zz ECU.

Reverse the change of the TPS connector wiring. This is self-explanatory.

Switch to 1zz injectors.

Switch to a 1zz MAF tube. It's possible to stretch the 1zz rubber intake to fit it over the 2zz throttle body - this has been done before. .

Add the bank 2 O2 sensor (needed by the 1zz ECU). You may need to use a 1zz stock header modified with a 2zz flange. This could be a sticking point, if the rules require a unmodified header.Or you could cover up the swap header with a heat shield and keep your fingers crossed that nobody notices.

In theory, if you do this, the ECU will think it is running a 1zz, and the engine will run as a 1zz. There's a good chance it will not throw any codes. Yes, there is a difference in the compression ratio between the two engines, and this requires different timing and fueling, but they should be close enough.
 

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Discussion Starter · #7 ·
To run 2zz with a 1zz ECU and not generate any DTC.

Reverse the engine harness changes of the swap. If you are using a MWR swap harness this would be easy, just remove the swap harness and plug the engine harness directly into the 1zz ECU.

Reverse the change of the TPS connector wiring. This is self-explanatory.

Switch to 1zz injectors.

Switch to a 1zz MAF tube. It's possible to stretch the 1zz rubber intake to fit it over the 2zz throttle body - this has been done before. .

Add the bank 2 O2 sensor (needed by the 1zz ECU). You may need to use a 1zz stock header modified with a 2zz flange. This could be a sticking point, if the rules require a unmodified header.Or you could cover up the swap header with a heat shield and keep your fingers crossed that nobody notices.
This is what I am doing as Plan A.

I already have the stealth manifold from DDPR (you can fit the heat shields over it). I just need to drill a hole for the O2 sensor in the fake port.

I passed smog last time as a 1zz. This time the smog guy was very surprised that it was rejected by the computer, he didn't notice at all it wasn't stock.

2zz.jpg


In theory, if you do this, the ECU will think it is running a 1zz, and the engine will run as a 1zz. There's a good chance it will not throw any codes. Yes, there is a difference in the compression ratio between the two engines, and this requires different timing and fueling, but they should be close enough.
Yes, this is the part where I don't know what to expect.
 

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Just the codes, but apparently it now identifies your ECU instantly and flags you.
I thought the ECU could only be identified past a certain model year...I'm not sure if that year matters in terms of Spyder production years. Cali is so far beyond reasonable with their vehicle reqs. It's crazy how much our various freedoms are so state dependent.
 

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Just the codes, but apparently it now identifies your ECU instantly and flags you.
um actually its checking the tunes on the ecu to make sure they are the same. a friend of mine who is a ex tech but now he works for the bar told me that it takes 17 -20 pages of info off your ecu.. so not just codes
 

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um actually its checking the tunes on the ecu to make sure they are the same. a friend of mine who is a ex tech but now he works for the bar told me that it takes 17 -20 pages of info off your ecu.. so not just codes
Interesting. Makes me wonder if the tunes is the same between different make/mode/year 1zz's (ex: 03's Pontiac Vibe) - and if that would trigger something.
 

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My initial thought was that one might be able to squeeze by with just the wiring reversal and 2nd O2 input (assuming the 1ZZ emissions equipment is still all in place). You would have to drive like granny (huh - neither of my grandmothers ever drove) and complete two drive cycles without codes. Shouldn't even have to swap the TPS wires (see Granny, above), if you can manage slow steady acceleration to constant speed and then hold it for 20 minutes or so (and then repeat the next day) before you plug in.
 

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If all else fails look into setting up an LLC in Montana & call it a day
 

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There are some misconceptions floating around about what anyone - including the State of California - can read from various ECU's. Toyota ECU's did not adopt an open J2534 architecture until 2005. After that date, calibration information can be read from the ECU, and the ECU's can be reflashed with edited calibrations (what you call toons). For those ECU's, anyone with the right tools can read the calibration ID and the checksum for comparison - which is all that is needed. Of course it is possible for freedom-loving patriots exorcising their individual liberties to code a fake vin, a fake calibration id, and manipulate the checksum, and pass - provided they can count in hexadecimal, which is the mark of the Beast. This is for 2005 and later ECU's. Before that, for ECU's from 2004 and earlier, sometimes referred to as K-line ECU's, the data available from the ECU is very very limited, and there is no possibility of reflashing the ECU calibration.

Another thing: using Techstream or any decent scantool, you can check the status of your monitors before you go for inspection. Torque pro for Androiod even gives you most of the monitor status.
 

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There are some misconceptions floating around about what anyone - including the State of California - can read from various ECU's. Toyota ECU's did not adopt an open J2534 architecture until 2005. After that date, calibration information can be read from the ECU, and the ECU's can be reflashed with edited calibrations (what you call toons). For those ECU's, anyone with the right tools can read the calibration ID and the checksum for comparison - which is all that is needed. Of course it is possible for freedom-loving patriots exorcising their individual liberties to code a fake vin, a fake calibration id, and manipulate the checksum, and pass - provided they can count in hexadecimal, which is the mark of the Beast. This is for 2005 and later ECU's. Before that, for ECU's from 2004 and earlier, sometimes referred to as K-line ECU's, the data available from the ECU is very very limited, and there is no possibility of reflashing the ECU calibration.

Another thing: using Techstream or any decent scantool, you can check the status of your monitors before you go for inspection. Torque pro for Androiod even gives you most of the monitor status.
This is exactly what I thought (I had the years slightly wrong in my head however). I remembered reading a bit about the early model ECUs not being able to be read in depth by the service computers when I was researching if a 2zz ECU would pass NYS inspection or if I would have to jump thru hoops to declare the car's modifications. Long story short I somehow found that info before finding out that NYS doesn't care as long as the ECU is OBD2 compliant.
 

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This is what I am doing as Plan A.

I already have the stealth manifold from DDPR (you can fit the heat shields over it). I just need to drill a hole for the O2 sensor in the fake port.

I passed smog last time as a 1zz. This time the smog guy was very surprised that it was rejected by the computer, he didn't notice at all it wasn't stock.

View attachment 82142




Yes, this is the part where I don't know what to expect.
If the smog machine rejected it. Then the car is already flagged to go to referee station.
 
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