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insert cool fact here
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Discussion Starter #1 (Edited)
First,
I want to thank all on this board for offering great, informative information on a regular basis. I have done extensive searching and haven't come up with the answer I am looking for.

I live in California, where smog is a big deal. This is my plan, please let me know if it is flawed.

1) I am leaning towards a BL stage 2 kit.

2) Swap ECU to OBD1 and use VPC or MAP ECU, possibly LS400 MAF

3) When smog comes around, remove turbo and manifold, and switch back to OBDII ecu, and install original MAF. I realize compression will still be around 8.8:1 with the 2.5mm headgasket.

Q1) is it possible to plug and unplug the ecu (switch to OBD1) without recording any codes, granted the battery is unplugged?

Q2) any problems with passing smog on a NA motor with lowered compression. I know it will affect turbulance of the air/fuel mixture, but shouldn't increase emissions too greatly.

Thank you
 

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BoostAddict4Life
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you have to change some wires to sensors from obd2 to obd1 im prity sure. if thats the case you would be rewiring the car everytime you go to inspection and back. to clear a code from the ecu just disconnect the battery.

id suggest swap in a tt motor, wont be smog legal all the time, but its real easy to switch back, ie, put the stock downpipe on again.
 

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I know CA is alot more difficult but that is what I am doing in GA right now.

I have a boostlogic kit that I run a obdI, LS400 maf, 550, headgasket and safcII. And here is the way I am setting up my car.

I have wired it with 2 maf connectors - 1 ls400 "obdI" and 1 supra tt "hot wire". I have also wired 2 connectors to my safc so that I can swap between the hot wire and the karmon settings.

I put in the OBDI computer I install the ls400 intake - tune car and bang - 450whp.

Emisions roll around swap out obdi computer for a obdii computer - change intake to the tt Maf and swap connectors on SAFC. Now you need to start the car drive it 5 complete cycles, warm up and complete cool downs. This sets the car to a ready state for testing. Ga does not have a visual inspection so I do not need to put the cat back on. As long as I am throwing NO codes, I should pass. You may need to lean everything out, add methonal and STAY out of boost for those 5 cycles to not throw codes.

I will be able to give you a lot more info on this by the end of the month when I have passed my emissions.

It sounds like a lot of work. The original set up and wiring will take time to get it right. but once you get the connectors wired up its easy. I can change my computers and intake setup in 30 min.
 

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1badlex said:
I have wired it with 2 maf connectors - 1 ls400 "obdI" and 1 supra tt "hot wire". I have also wired 2 connectors to my safc so that I can swap between the hot wire and the karmon settings.
Very nice!

One question for you: Besides changing the MAF back and forth, do you have to change anything else when swapping the OBD1 and OBD2 ECUs back and forth?

Some have said that other sensors have to be rewired, but I have a feeling they're just passing on rumors they have heard.
Can you please confirm one way or the other?

Thanks,
~Alan
 

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SPORTcoupe said:
Very nice!

One question for you: Besides changing the MAF back and forth, do you have to change anything else when swapping the OBD1 and OBD2 ECUs back and forth?

Some have said that other sensors have to be rewired, but I have a feeling they're just passing on rumors they have heard.
Can you please confirm one way or the other?

Thanks,
~Alan
The only sensor that I had a problem with when I swaped to obdI, was the power steering sensor. It kept poping the fuse. I just disconnected the sensor at the pump and everything worked great.

The MAF and your SAFC are the only things that have to be rewired. I hope to put the turbo back on the car tomorrow. I will then set the safc to zero and drive with no boost for 5 complet cycles. If i get any codes I may lean it out using the safc or just put some methenal in. I Hope to go on Saturday to test.

I am running No cats and no o2 sim. What I did was move the after cat O2 way down my mid pipe.

I will try and write it all up if I pass.

This is on a 2jz-ge in a 97 sc300. Everything I have seen for a supra NA are the same. I am not sure what is different with a tt supra. But if someone has the wiring prints for the ECU I could look into it.
 

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Just a quick update.

I have swapped back in my OBDII ecu and have hooked up the tt maf. Right now I have completed 2 cycles, start drive - let cool, then repeated and have "0" codes. Everything is saying "pass". This is a good sign.

Back ground on car - running t61 single turbo, no cats, custom exhaust, 550 injectors, headgasket, after market fuel pressure regulator, msd ingintion, and safcII. Boostcontroler is turned off running wastgate spring - 15lbs.

I am hoping to do 4 more cycles with no codes. I should be able to take it for emissions testing on Monday if everything still looks good.

;)
 

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insert cool fact here
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Discussion Starter #11
Sounds good, and good luck. When I do this, I am planning to go back to the original ECU and stock Hotwire MAF when E-testing comes around. I have heard that 5 complete cycles is enough, but I have heard otherwise as well. Let us know how it goes.
 

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Well got GREAT NEWS.

I passed emissions here in GA on a OBDII car. Ga does not have a visual inspection. I went to just any test site and paid the regualor fee. No buddy system.

But my quesiton is if I can pass emissions with no cats, legally. Why do I need them?

5 cycles is all you need to put the computer in the ready state. I drove it 5 miles on each cycle and on the 5th I went straight to the emissions place. And it passed with no problem. I almost wish I had tried it at 3.

Quick mod list -

Stock OBDII ECU
boostlogic kit with a T61
550 injectors / headgasket
SAFC II / aftermarket fuel pressure regulator.
MSD ignition
Supra TT MAF
HKS cam gears

No fuel adatives AND NO CATS AT ALL.
 

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Mark 2JZ said:
1badlex, any issues with having to reset the obd2 ecu every once and awhile? does it fight your SAFC settings at all?
Simple answer is YES. That is why I only run the OBD2 computer during emissions. I am going to swap back to a obd1 computer tonight.
 

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idrewfelix said:
I heard some people just bribe them out :p

Yes, I thought I may have to do that too but when I started this project I wanted to have a 400 + whp car that could pass emissions without having to bribe anyone.

And I did it. Now I am going for 500+. :p

I know you guys in CAL have it a little rougher but I hope that this information helps some.
 
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