Odd ignition timing vs emissions

[jerseydevil]

I know emissions tends not to be a top priority around tuning circles but I still need my car to pass NJ state. Which it did this morning!! First time in 6 years thanks to being able to use ectune/demon altering shit on the fly during the test. So here's what happened and I'm hoping the car guru's out there can help explain what the hell is going on. I pulled up with the car all warmed up, cat hot, runnign on the honda stock computer (basically stock gsr/p72). We stuck the probe into the tail pipe and the HC jumped way upt to 850ppm! Holy shit, it's incredibly high, the limit was 220ppm. CO limit was 1.2% and it was reading 3%. NOx isn't tested anymore so it wasn't displayed. If i remember right co2 was 11%, but that coudl be wrong as I wasn't paying too much attention to c02 at the time. Basically honda computer failed big time. So we loaded up ectune and switched over to the demon. We ran the machine while I was changing things. Tried leaning it out to reduce HC which had a very minimal effect. Car was running about 17.5:1 and HC only dropped down to 600ppm. (these are no load tests, idle and 2500 rpm). Next I started pulling ignition timing to see if that would help. Low and behold it did. Started with 2 deg. and it dropped 100pm. PUlled more and more. I endedup having to pull a full 16 deg! to drop the emissions down a passable level. During the test phase we were getting @20ppm HC and .3 CO 13% co2 .1%02. I later got home and recheckedmy timing at the dizzy, which was perfectly spot on at 16 deg. I used the ignition synch tool to check it. During the whole thing there was very littlel effect on how the car ran. Which shocked the hell out of me. Running at 17:1 and 0degs advance it idled perfectly smooth and ran at 2500 rpm perfectly smooth.. no missing at all. I didn't dare run it like that with a load on the street, I switched back to the honda ecu before I left the place. Anyone have some insight in what is going on there?

[Vtec6000]

That is strange normally advancing it should help lower the emissions. Have you cams installed?

[JaredKaragen]

That is strange normally advancing it should help lower the emissions. Have you cams installed?

Not exactly... depends on fuel and what emissions it's high on. I touched on this in another forum; valves are larger... Makes a world of a difference. You can get any dirty runner to pass smog if you retard ignition enough.... No joke.