Passed my CA dyno smog check. barely...

[Prez808]

Well, this was the first time I had to get a smog check on the new dyno test machine (no, they didn't measure horsepower). In the past, the test just included putting a sniffer up the exhaust pipe and measuring the engine while stationary. Now the test is done on a rolling dyno to more accurately recreate actual conditions.

It was a little alarming to see that max allowable NO @ 15 mph is 791 ppm, and my reading was 787. Also at that speed, the max allowable CO% is 0.74, my reading was 0.70.

Since in the past, the techs would say that I passed with flying colors, what's up with the near failing readings? The guy at this place said the reason for such high readings is likely to be a clogged EGR (not likely, since it was unclogged 2 yrs ago) or a clogged catalytic converter.

Are any of you guys getting readings like this? Any honda techs have any ideas what's up?

Thanks!

[90Accord-R]

I went in once and it failed on NO and HC's, but the motor hadn't run very long. The guy said it was probably a bad cat-converter, and he knew a place that would replace it cheap. The next weekend I took it back, but took it for a hard run through a local canyon road first. Turned out the cat just wasn't hot enough yet to work properly. The second tech said he recommends driving the vehicle at least 10 miles before any smog check. Obviously the first tech was a "dirty" mechanic.

[Prez808]

Yeah the car was only driven about 2 miles before getting there, although it got to idle a while before they tested it. I won't get a cat until it cannot pass.

[accordztech]

NO is egr...

hehe u should of saw mine...hella low wiht their new tests..

----------
welp i passed with amazing results.

***********15mph test:*************
co2%- 15.20
O2- 0

****its hard for me to fix this so here is the format (maximum--average--measured)***

HC(ppm)-(118--31--20)
CO(%)-(.75--.10--.07)

NO (ppm)-(799--237--373)

**********25mph test***************
co2-15.10
o2-0

(maximum--average--measured)
HC(ppm)-(93--20--9)
CO(%)-(.63--.09--.01)
NO(ppm)-(738--199-436)



and this is with my old manifold that never was cleaned out...

[NutBucket]

Nice work ztech. That's about the kind of numbers my F was getting as well.

Hopefully this H won't be a huge pain in my ass. I expect a small one Can't be too optimistic

[mrhonda]

well, if you already cleaned your EGR ports, than its gotta be the cat.

[Prez808]

Could a part of it have been that my car wasn't hot enough yet? How long does it take to get to the optimal operating temperature?

[accordztech]

the cat has tobe around 500 ddegrees or something

i just run the car for about 30 minutes at max power.

[90Accord-R]

Yeah a 2mile drive, and just idling are not enough. You really gotta run the crap out of the motor to heat the cat to optimum temp. Plus a few hard acceleration bursts help blow out any carbon buildup in the cat. Also, if you're due for an oil change, that can increase emissions too. Old oil is thinned out and works it's way through seals, burning a bit. This is usually on higher mileage cars tho...

[Prez808]

well 2 years have since passed, and I was due for another test. This time I had to go to a test only center since my car was flagged for being a high emitter. Well needless to say I passed with flying colors! I was sure to drive at highway speeds for 30 min and floor it a few times. That did the trick.

[wed3k]

worry about in the next two years, our camry barely passed like the numbers were dead on but it has the original cat..too abd the original cat costs 300+ dollars.

within the next two years, it is getting junked anyways.

[f22a4bandit]

Congrats! I'm glad that I live in a rather small town when I go to school in Texas, I don't have to deal with emissions testing. I'm sure I would pass, but who knows.

[4CYLPOWER92]

This time I had to go to a test only center since my car was flagged for being a high emitter.

I've had to go to a test only center for the last 2 or 3 smog checks. I'm guessing it's required because of the age or milage of the car, because my car has never came close to not passing.

But this latest test was the worst so far.

................(Max...Ave....Meas).......(Max...A ve....Meas)..(Max...Ave....Meas)
15mph.(HC....116....31.....83.....)(CO,,,.74,,,,,. 10,,,,,.31)(NO...791...237...243)
25mph(HC....91......20....48......)(CO,,,,.62,,,,, .09,,,,,,.20)(NO...730...199...99)

That was with 219,700 miles.

[accordztech]

pretty good numbers, nothing to worry about next time.