Rogue_Ant

NCLA951 - how long was the car running before you took the test?

You are definitely a little rich. How old is the O2 sensor? What FQS position did you take the test in?

That high of NO tells us the cat really wasn't working... was it because it wasn't hot enough, or it didn't have the proper precious metals as Humboldtgrin mentioned - IDK.

The A-Tune has been on hiatus for a bit now... Looking at offering it again, either direct, or through Lindsey Racing.

NCLA951

The car was running for about 10 minutes and run at high rpm to the test place to heat it up, but will run it longer next time to get it hotter. It was the free flowing magnaflow so maybe the substrate is not dense enough. They make one in the same size that they say is more effective (i.e. It doesn't trip codes in odb2 cars), I may swap one of those in if next try doesn't work.

O2 sensor is about to be brand new, don't know age of current one may be original.

FQS is in position 1 with welt chips, I don't know if those chips follow same switch settings as factory?

NCLA951

Also A Tune sounds rad, bring it back!

Rogue_Ant

Yeah, as I mentioned, touch the tail-pipe. If it isn't hot, then you need to run the car more/long/high-load.


O2 sensors have a finite life. As they age, they typically get slower, and read 'leaner'. This will cause the DME to add extra fuel.


The FQS of the Welt chip are the same as factory. So, on position 1, you were adding an extra 3% fuel.

NCLA951

The FQS of the Welt chip are the same as factory. So, on position 1, you were adding an extra 3% fuel.[/QUOTE]

Sorry meant 0, not one, all the way down.

Hopefully this O2 sensor does all or some of the trick.

Rogue_Ant

Just for clarification... Position 0 is all the way counter-clockwise.

Is that the position you had it?

NCLA951

Yes stock, like turning the clock back to midnight. Checked when I discovered the welt chips (PO knew chips, but not type).

Day after Xmas I'll get the sensor in, and see what happens. I do not have an afr gauge/wideband O2 installed, so have no way to check rich/lean when adjusting FQS. My instinct would be to run 3-6% lean for emissions testing, and hope the hotter exhaust keeps the heat in the cat longer when running a little lean at testing RPM, which is certainly not science. But I also don't feel the engine has been running hot, it never gets above the 1st 1/3 water temp mark and oil pressure never goes below 2.5bar at very hot idle, so I don't think combustion temp is the source of high NOX, but again that's anecdotal, not direct measurement.

I have plans to install afr and boost gauges in the glove box to keep the interior stock looking, but until now that has been low on the project list.

Any and all input is appreciated in this, in order to drive this thing, this is the first thing I need to get taken care of (I didn't think it would be an issue), and as I have sold this purchase to my wife who is about to have our first son as my daily with a 'back seat' I kinda have to make this work!!!

Thanks!

Humboldtgrin

I'll be honest and say theirs not to many rennlisters who took California smog class like I have. There from all over the world and don't have our strict smog laws. And the only reason for NOx is high combustion temperatures, leaning it out will make it worse. The advise I gave you will have you pass. Sorry if you don't have or want to put the stock cat back in temporarily, but that's the ticket. If you have a custom down pipe with a bigger flange then have a bigger flange welded onto your factory cat for smog tests each year. I have helped with the best possible advise that I am able to provide. Good luck.

Laust Pedersen

This generic emission graph from "Automotive Electrics/Electronics" by Bosch should help a lot in finding where the problem(s) may be.

wwhalenc

Interesting graph. I've heard that a well tuned/maintained car can pass emissions without a cat. The graph sure makes that seem pretty hard to pull off (at least here in the Denver metro).

PEvans

I don't think that is true anymore if you have to get to ~700 ppm NO. You will have to have a cat, and working pretty well at that.

In this case the OP has to sort out the HC also.

Arominus

The 28 pin conversion is cake, i did it for another lister in a few minutes with Joshes kit (he had the DME open for me already). easy easy easy if you've ever soldered at all.

V2Rocket

To fit the test conditions, just gotta make sure your car is to temperature, running as close to stoichiometric (14.7:1 AFR) as you can, and a good condition catalytic converter.

After I put on the vems system, I'll make a "CA smog test tune", let it auto tune for 14.7:1 as needed and I'll take it to the smog guy to see how it runs through the crucible... (Off the record pretest).

Luckily, visual check is only in the engine bay and the guy doesn't check the DME.

JacRyann

Spence, be careful about CA's pre-test. It's no longer completely off-the-books. Even though you don't get a cert, it's still logged into the system. Too many failed pre-tests can get you flagged.

The NOx results are odd. Note that many free-flow "performance"' cats are only 2-way and doesn't deal with NOx.

1. Is the cat installed backwards?
2. What is vacuum at the FPR nipple at idle with warmed-up engine?

NCLA951

Cat is 3 way, but I have some other ideas I'm going to chase down, and will check vacuum at warm idle after I pick up a vacuum gauge.

Thanks for all the input, will report back.