Thread: How to: Pass smog (Nismotronic+Wideband)

Do you run 3 bar or 4 bar fuel pressure?

3bar

I am confident it will pass, but some of you already saw my thread about me breaking the handbrake (http://www.sr20-forum.com/general-sr20/74698-pulled-handbrake-too-hard.html)
This in turn made me postpone the final inspection, so expect results 28.7

4:th attempt

Result: Pass


These were the readings. Nismotronic settings, "Enable Closed Loop" [X], "NB02 Closed Loop" [X].

I deviated from the first post, and passed using the narrowband output. Still, I was technically using feedback from the wideband?

Huge stone off my chest

Glad to hear you passed!

You were using the simulated narrow band output from the wide band, right?

Dave

Yep,

To get it to make quicker calculations, I disbled closed loop, and tuned to 14.7 afr for these no-load cells

Don't know if it helps alot, but in theory it should?

I want to bring this back from the dead

So I went for emissions yesterday and took my laptop with me to do live A/F correction. The tester had zero issues with my adjustments during the test and wouldn't you know, the damn thing passed, and passed with plenty of room to spare! I had to ask the tester twice if MY car passed, then I stood there for a few moments, baffled, and proceeded to ask him if he had the right car..........He just laughed and sent me along my way!

So needless to say, I don't have to worry about tags for another almost 2 years! If I failed I was just going to park it until the New Year and just get historic tags, but now I can sit on that for a while and get those tags when I feel like dealing with the MVA


Setup:
Sr20DET
EFR
Nismotronic
ETC

Happy as a fat kid with cake

Time to bump this thread again with more info!

I had some trouble passing smog again this year, it took me two retries until I solved it. My setup was pretty different from last year, MAF->MAP, 370cc->STI 555cc and some other tweaks.

The problem was my injectors. The STi injectors just wasn't even enough. In closed loop my AFR switched between 14.0->16.0 rapidly. This was the first smog test:


After realising this, I switched to stock DE 259cc injectors. I did nothing else except tune accordingly. I now have AFR pending between 14.5-15.0 This was the result:


So, if you have big CO emissions, try switching to more balanced/smaller injectors.

Anyone else passed smog with big injectors?

The setup I passed emissions on was on S15 injectors (480cc @ 3 bar) @ 4 bar (~520-530cc)

Yeah, I'm just gonna assume my STi injectors are bad, since I could pass with 370cc injectors just fine.

I also remember reading somewhere that John tuned ID1000's to pass smog? Or was it for stable idle? Anyways, a new set of injectors is on top of my priority list atm

The top feed ID are much more consistent in regards to operation. The sidefeeds will always have a longer "lag/latency" (opening) time than the IDs and if you are running low pulsewidth, this lag time translates into unstable A/F at times.

But, the STI injectors shouldn't be an issue as is (read: in OEM config without the cap removed/modified). STIs pass emissions all the time, less we not forget