obd2 and turbocharging

[yoozef]

Im thinking of going turbo on my 98 240, but am not sure about few things. Mainly if i go ka-t will i be able to pass NYS inspection (they just plug into your ecu and check for codes) without removing the turbo kit every year. Since it's obd2, i can't run an aftermaket ecu, but if i buy a kit and run stock psi would that trigger any codes? is that possible? sorry for noobness, but would really like for someone who's experienced to shed some light, thanks

[480sx]

You can get an OBD2 Ka-T to pass emissions. However, your kinda limited to the amount of power you can produce with the motor, or simple, how much boost you can run. Taking it past 8-10 psi and those OBD2 sensors, valves, solenoids, ect are going to take a beating. They can also leak or burst at higher levels of boost.

The main concern with getting an OBD2 Ka-T past emissions is the EGR system. You will have to either trick the EGR into thinking its still operational(i THINK this may be possible with a simple jumper resistor..) or you have to make a custom EGR pipe that connects to your downpipe. That is just generally a pain in the a**.

You also have to remember you need to hook up your secondary O2 sensor into whatever exhaust you decide to run unless you run the stock exhaust system. You will probably need an aftermarket CAT or the secondary O2 sensor will throw a 'to rich' code.

[yoozef]

so if i bought a basic turbo kit and ran it on stock ecu it would work? im a noob when it comes to anything turbo related... thanks

[480sx]

Just run a FMU and 7-8 psi with a 2-3 degree base timing retard.

[motoman399]

Just run a FMU and 7-8 psi with a 2-3 degree base timing retard.

how many times do you think you have written that exact thing lol

USE THE SEARCH

[480sx]

[C-Kwik]

I had run a 98 240sx with a turbo and it had no codes when I ran it with a Greddy E-Manage. The EGR was blocked (not removed)as well. Hell, it even managed to pass the sniffer portion of a CA test (smog shop ignored the visual). Of course the NOx emissions were a bit higher than it should be, but was still within the limits. With an FMU, it did throw a code (I can't recall which as its been so long). My guess is that since the E-manage controlled fuel by altering the MAF signal, the ECU never picked up on a signal that was outside of any particular range for the airflow rate that it believed the engine was receiving. I also never ran it over about 7 psi on a T04B though so I'm not sure if things would change as airflow increases further. I also did not run a catalytic converter and no O2 sensor codes were thrown.

[480sx]

Hmm maybe there isnt a sensor that determines if the EGR system is actually recirculating gas and the system will 'work' regardless of if it flows anything or not. I know my customer had the same basic thing done to his car for a while, it was just plugged. I dont think he had any codes either, with the Greddy kit on a 97.

As far as the O2 sensor goes i was speculating, i know a screwed up cat can trip up the post cat o2 sensor or trip random ECU codes, so i figured removing it might do the same. Guess not on a 240.

I hate DDing a car without a cat. Kinda like, hey, eff you to everyone behind me all the time lol. I also like to minimize the amount of black smoke my car puts out after i roll it from vacuum to hard boost. In addition, a high flow cat + resonator with a 3 inch exhaust and a decent muffler sounds great. In most situations as well, a high flow cat isnt really going to disrupt flow or decrease HP by what i would call a significant level. Anything thats consistently over 350-400 hp going out a 3 inch, i would consider removing the cat, but below that HP level i just cant see it being worth it. Ignoring the fact that its a federal offense lol.

Really am curious as to what code you threw as you say.. kinda... excuse me if i have this wrong, 'Because you installed a FMU'. I dont know thats not really making any sense to me heh. There is no fuel pressure sensor or ties with the fuel pump-ecu besides on/off. Idk, just wondering. Maybe there is an electrical load difference on the injectors significant enough to trip up the ECU from 38 psi of fuel pressure to eh.. 80-100 with boost and a FMU?
Modified by 480sx at 8:02 PM 8/4/2009

[SpeedmanRC]

Only thing the SX dose for EGR is if it's plugged in. no pressure sensors like most fords.

and you can run the down stream O2 with a spacer witch should help that "efficiency" code...it's not very efficient when no cat is there, lol.

I'm also looking for some light on this. I'm working to get boost in both my SX and wagon...but the legacy will just get a WRX swap and be fine for OBD2

[C-Kwik]

Hmm maybe there isnt a sensor that determines if the EGR system is actually recirculating gas and the system will 'work' regardless of if it flows anything or not. I know my customer had the same basic thing done to his car for a while, it was just plugged. I dont think he had any codes either, with the Greddy kit on a 97.

My guess is its a passive sensor of some sort. Perhaps detecting an EGR failure indirectly or only sensing if the EGR isn't opening or something. A blocked EGR would still register as opening, but wouldn't be reducing the NOx emissions.

As far as the O2 sensor goes i was speculating, i know a screwed up cat can trip up the post cat o2 sensor or trip random ECU codes, so i figured removing it might do the same. Guess not on a 240.

I actually expected the same, but it never came up. I wasn't about to question it.

I hate DDing a car without a cat. Kinda like, hey, eff you to everyone behind me all the time lol. I also like to minimize the amount of black smoke my car puts out after i roll it from vacuum to hard boost. In addition, a high flow cat + resonator with a 3 inch exhaust and a decent muffler sounds great. In most situations as well, a high flow cat isnt really going to disrupt flow or decrease HP by what i would call a significant level. Anything thats consistently over 350-400 hp going out a 3 inch, i would consider removing the cat, but below that HP level i just cant see it being worth it. Ignoring the fact that its a federal offense lol.

Problem for me was the downpipe pretty much eliminated the use of the factory cat. Which meant I had to use an aftermarket cat (which likely had much less precious metal content; which could mean it might wear faster). Couple this with the increased NOx and HC load from the turbo (and the use of an FMU) and I decided to pull the aftermarket cat so I can save it for the next smog test (the smog shop I used ignored the visual but still checked the actual emissions). Made much more sense to me to do that rather than risk having to buy a new cat each time. Not to mention if I got pulled over and my underhood shcked out, then it was illegal regardless, with or without the cat. And few people stayed behind me for very long.

Really am curious as to what code you threw as you say.. kinda... excuse me if i have this wrong, 'Because you installed a FMU'. I dont know thats not really making any sense to me heh. There is no fuel pressure sensor or ties with the fuel pump-ecu besides on/off. Idk, just wondering. Maybe there is an electrical load difference on the injectors significant enough to trip up the ECU from 38 psi of fuel pressure to eh.. 80-100 with boost and a FMU?

I wish I could remember. For all I know, it could have been EGR related. But the inference I was making was that the code didn't exist because of the FMU. But rather using the E-Manage got rid of it. Which is why I mentioned my speculation that the signals that were monitored were simply within range in relation to the MAF signal since the ECU sees less airflow with the E-Manage coupled to larger injectors for a given actual airflow. AS an aside, I would expect similar results with a SAFC as it essentiallyscompensates the same way.

[bikrman2]

Here in NY it's tough to say. I'm debating the same thing with my '96. The problem lies not only in not having a check engine light but also having no more than 2 readiness cycles incomplete at the time of inspection. I think if you stay with a pretty mild setup and use a piggyback such as the e-manage you should be fine as long as everything is tuned right. The other option is to be an inspector working in the shop doing the inspection like me! lol j/k.