Making an OBD2 SR20?

[GEARZ]

Yes this is my first post but i do know a bit about cars. So my question is what is holding everyone back from making a program, or an ecu for a sr20 that could be programmed with either real emissions related things such as egr, o2 sensors, evap, and what ever else, or one that uses fake substitutes. it just seems to me that with all the programming that is possible that there has got to be a way to make a legit OBD2 SR20 that could communicate with all the sensors through a scan tool, and if the sensors don't exist, there have got to be some kinds of a substitutes. idk but im hoping that you guys either know why its impossible or have seen it done.

[bardabe]

one good reason is because the SR20 never had EGR, then comes the factors that an OBDII was never made in japan and ofcourse wiring for the scaner tool will also be somehwat of a bitch to do properly. so there is alot of work. not to mention that in the end it still would not be legal because RWD SR20DET was never produced int he US so it will not pass LEgally no matter what we do.

[GSXRJJordan]

SR20s do have an Exhaust Gas Return, and s13 SRs have an AIV also. One pumps exhaust gases into the intake to cut down on NOx emissions, the other pumps fresh air into the exhaust to lean out the CO (unless I have my emissions backwards).

Anyway, the problem isn't getting an SR to pass the OBD2 Diagnostic test, that can be faked - the problem is getting it to pass the visual test. If you're interested in making SRs legal, please visit www.legaljdm.com (http://www.legaljdm.com), or check out Joe @ Rec Productions' thread(s) here on zilvia.

[GEARZ]

i know it will never pass a visual inspection, but i dont really have to worry about that in AZ. Im just trying to figure out if anyone has ever made an OBD2 compatible SR20, either with emission parts from other US cars or with an ecu programmed differently

[myzislow]

I have mine wired to a obd 1 port just to monitor engine vitals with consult2, if you have access to a consult, I can tell you how to wire it( its pretty easy, 4 wires)

[projectRDM]

I have mine wired to a obd 1 port just to monitor engine vitals with consult2, if you have access to a consult, I can tell you how to wire it( its pretty easy, 4 wires)

That's a CONSULT port, not an OBD port. Two completely different things.

[i need tires]

Hungry Adam on az240sx.org said that if you get a 96+ SR he can get it to work with your OBDII connector so you can pass emissions with it... im sure it will cost you a pretty penny to have him do it but he is a pretty smart guy and he can defiantly get it done for ya! so post this up on az240sx.org

sorry his username on az240 is Tyler Durden

[myzislow]

That's a CONSULT port, not an OBD port. Two completely different things.

how are they different? you plug consult into an obd port, its the same thing.

the only difference is the wires ,if accessing obd functions with a non nissan diag scanner or smog machine, it uses a dedicated "k-line".

btw, I was just offering some help on realtime data monitoring options.

[i need tires]

how are they different? you plug consult into an obd port, its the same thing.

the only difference is the wires ,if accessing obd functions with a non nissan diag scanner or smog machine, it uses a dedicated "k-line".

btw, I was just offering some help on realtime data monitoring options.

there is a big difference man! the obd2 connect reads if anything is wrong with the car, the consult port is in both OBD1 and ODB2 cars.. the difference between the too is the obd2 port connector usually on the left side of steering column towards the floor

[myzislow]

there is a big difference man! the obd2 connect reads if anything is wrong with the car, the consult port is in both OBD1 and ODB2 cars.. the difference between the too is the obd2 port connector usually on the left side of steering column towards the floor


its obvious youve never used a consult scanner, IT PLUGS ITNO WHAT YOU ARE REFFERING TO AS A "OBD PORT" also known as a ddl.

argue and flame if you want but I use one everyday.

[i need tires]

you can use a consult port on a non obd2 car correct?

[myzislow]

you can use a consult port on a non obd2 car correct?

consult2 has two different adapters one for obd1, and one for obd2, anything older than that you have to use a"checker box".

[projectRDM]

You're full of shit. the CONSULT port is a Nissan only plug that only the CONSULT tool and Techtom components plug into.

The OBD plug is an industry standard connector that any scan tool made will plug into, whether it's OBD-I or II the plug is the same, so is the software to run it. Only the codes change between the two systems.

The SR ECU does not have the OBD feed wire to run a diagnostics on. It does have the three CONSULT feeds (RX, TX, CLK) and you can use that just like any other 91+ Nissan chassis, but the OBD port doesn't do shit for an SR, RB, FJ, or anything else non-US sourced.

Japan does not use the OBD standard on their cars and therefore does not build the chassis or engine control system to accommodate it, especially on anything pre-2000.

You need to realize the difference between the two before you talk out your ass sparky.

[mifesto]

i think he's just saying he had it wired up to the odb port. doesnt mean it is ODB compliant. sorry for old bump... any progress on such a work?

[98s14inaz]

I've discussed this with several people after my last emissions test in Arizona. I have an obdII s14 and failed emissions the first time through because the computer wouldn't communicate with my car. I made them retest it because the check engine light functioned the way it should. I passed. The funny part was that they never opened my hood or looked at anything.

This got me thinking. I've owned three of these cars, there are only a few sensors that the obdII system reads. Why couldn't you run two ecu's. One manages the engine and other important stuff, the other simulates the obdII crap via resistors. As long as it has the correct values, makes the cel function correctly, and communicates with the obdII plug, then it should work.

[mifesto]

well the "second" ecu would need to receive certain voltage from such things as o2 sensor etc etc.... not sure if soldering a "Y" into those signals would be sufficient.

[g6civcx]

This got me thinking. I've owned three of these cars, there are only a few sensors that the obdII system reads. Why couldn't you run two ecu's. One manages the engine and other important stuff, the other simulates the obdII crap via resistors. As long as it has the correct values, makes the cel function correctly, and communicates with the obdII plug, then it should work.

This is more complicated than it sounds. Try it and see.

[98s14inaz]

This is more complicated than it sounds. Try it and see.

It is a theory and I realize it is a lot of work. I've done wiring and engines for years. The real challenge for me is finding time to work on it. When I do, I'll make sure to document it. I am just throwing the idea out there.

[just1pepsi]

I did some trickery on an o2 sensor to fool the ecu into thinking there was a catalytic converter when there wasn't in order to keep the CEL off by soldering in some resistors inline with the return wire.. It worked for awhile, but was unreliable. I'm sure something like that (stand alone ecu w/ obd to pass an emissions test) would be possible with the right amount of knowledge and expertise. Something tells me that since its only purpose is to bypass state law is the reason such a thing does not already exist.

[g6civcx]

An O2 signal generator can be bought or homemade, but an entire OBDII simulator would be challenging.

It would probably be less work just to make the car OBDII instead of building a simulator.