Made some chip changes that helped a lot, but still not enough to get me under the limits. NOx are SLIGHTLY high, I failed CO by 1 point, and HCs are very slightly over the limit. So close on all counts, but still too high. Only for the 15mph test. 25mph test it passed across the board. Cat is about a year old, but I think I might have fried it running open loop for about 6 months while I was tuning. Is this possible? Not sure. O2 is coming through which says lean, but HCs are high which says rich. Don't get it. Tested EGR and it seems to be working just fine. Got 60 days to work this out...

HC is NOT an indicator of fuel mixture. Post your VIR. Let me see, maybe I can help you .

We don't have emissions testing in Florida but I'm curious. These questions may not have a simple answer - Would new third gens have met the requirements? What's the oldest make year which would have met the requirements when new?

This was the first one.



I realized afterwards that the car was running rich due to my new fuel pump putting out 2 PSI more than my old one, and that I was running TONS of timing advance compared to stock. I pulled some fuel and pulled some timing, and went for a drive. BLMs and WB AFR was PERFECT. I even datalogged during the second test and my AFR was right on the money throughout.

Second test results:



My changes helped a lot, but not enough. Don't know what to think. The car has had a complete tune up within the last year or two. I'm planning on checking my plugs for any inconsistencies. I tested my EGR by pressing up on the diaphragm and it killed the engine like it should, this means it's working, right?

I'm very much a man of science, but after scouring the internet I have yet to be able to find some PURE SCIENCE about what these numbers mean at the molecular level. That would really help me troubleshoot my own problems.

egr should also hold vacuum.

looks like your passed NOx by a little on the second test.

if I remember right CO2 is like cat efficiency, and that looks ok.

with a rich mix your NOx would be low. Im thinking maybe timing or something ignition related.

just a guess on the little I know about smog

Where in the rpm range did you pull the most timing?

Can you adjust it even more in the lower rpms just for smog purposes then raise it back up afterwards?

Over here in San Mateo we have these smog "fix it" stations that 'force' the car to pas. They know all the tricks. I was amazed at the low readings they were able to get on my car after the first failure.

But it costs...

Nox is from too much heat and or pressure, causeing nitrogen to bind with the 0xygen.
That is why a egr takes exhuast gas and dilutes the air. Basicaly adds inert gasses to reduce the combustion temps. high nox can be caused by too lean or too much timing.

Co is incomplete combustion. Which means that you have to much fuel.

Hc is unburned fuel. that means it didnt burn at all. Thats caused by a missfire, either igintion ( bad plug) , mechanical (bad valve) or Extreme
leaness or richness.

o2 is left over oxygen. Means theres not enough fuel. You compare co to o2. If o2 is higher then co you are lean, if co is higher then o2 you are rich.
Notice you dont look at hc to see if your rich. Hc is a missfire indicator.


Co2 is good, more the better. Co2 is what you get when you have a good afr. The higher the c02 the better your burning the fuel. Means both the mix, ignition and the the mechanical parts of the motor are all working good. 12- 14 percent is a good number for a motor with a cat. 8-10 for no cat.



In your case, you have a tad too much timing advance. This is causing the hi hcs (a slight miss) With the miss you could get a little higher 02 reading. You could also have a tad to much fuel still. The high co indicates this.

I read somewhere you guys in FL are getting smog checks soon. Good luck!

Supposedly the CA smog check is not any tougher to pass than when the car was new back in the 80's. But I wasnt driving in the 80's so I have no smog check records to verify that.