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Gross Polluter???

10 November 2001
Orange County, CA
Man oh man! Everything was going perfect. I finally got my car (91) in Southern California shipped from Minnesotta.
Went for a smog check today and it failed! The machine said it was a gross polluter. The hydrocarbon number (dont know what that means) was very high beyond the max. Anyone know why this might be? I left my car in the hands of NSX Modified tonight...GO LARRY!!!
Seriously though,the car feels and drive fine and the Acura dealer tech in Minnesotta said everything was good. Compression/leak tests were good, CARFAX and Consumer Affiar reports of the VIN turned up clean. It has very low miles (30K) and looks/feels brand new. It was never driven in rain or snow. No mods whatsoever.
This is frustrating...I just want to get it registered and have fun with it
Does not driving the car for months affect the smog? I did warm it up before taking it in. Anyone know what might be up?

[This message has been edited by max_payne (edited 27 November 2001).]

[This message has been edited by max_payne (edited 27 November 2001).]
I'm sure Larry will figure it out. One thing that should be taken care of automatically is the ECU should adjust the fuel mixture for your new attitude. Sounds like something is preventing to from occuring correctly is all I can figure and that's why you're running rich. I wouldn't sweat it too much. Larry will figure it out.
lol............................i'm sorry i had to laugh, hope you get it figured out.
i could just picture a face of a nsx owner when he hears the words "fail"
When I first bought my NSX I couldnt pass the smog check. After diagnosing the whole car, it turns out that the previous owner gutted the catalytic!!!!!! There is no way it will pass...
A new catalytic from the dealer is $1000 each so $2000 for a pair. Luckily I was able to get a hold of a used catalytic for $200 a pair. After instaling the cat the car passed with flying colors.

G luck
Per my friendly smog checker, Honda engines are some of the cleanest he sees.

As I posted in another thread this evening, check the computer for codes.

[This message has been edited by nsxman (edited 28 November 2001).]
High HC's are because your vehicle is running to rich. If your vehicle was not warmed up before you had your test done then it would be most likely that. Be sure that you drive your car for awhile before taking it in and make sure that you don't have to wait so your car doesn't cool down. Your converter will only work if your car is warm. You may try some tricks about leaning your car out but don't go to far because then other emissions will rise up. You could try some really shitty gasoline aswell. I have heard this works great, some of that usa gas 87 of course.
Originally posted by primetime_vtec:
Be sure that you drive your car for awhile before taking it in and make sure that you don't have to wait so your car doesn't cool down.

I was told sometime ago that in order to have the best results for the smog test/emissions, you should drive your car for 30minutes(not leisurely driving) prior to the test and never shut your engine off while you are waiting in line. Hotter the engine and exhaust, the better the results.

If that's not the case, then failed HC tests usually result from compression or ignition problems. Improper fuel mixture and vacuum leaks will also cause misfires that will cause excessively high HCs. I would check the ignition system first as ignition miss is usually the culprit there. Then check the engine next as poorly seated valves, leaking head gaskets, or other compression problems will put the HC readings through the roof. Also check for vacuum leaks and the injector spray patterns.

Hopefully scenerio 1 was the culprit there. Good luck!
When I had my NSX smog tested in April of this year it failed due to high hydrocarbons as well although it seemed to run perfectly. I took it to the local Acura dealer to have them check it out and it turned out that one of the O2 sensors was corroded (their term) and when they replaced the sensor, Voila, it passed. Hope that helps.
"... and the Acura dealer tech in Minnesotta said everything was good."

Yeah, well, the tech that did the inspection on my NSX before I bought it failed to notice that it had intrax lowering springs on it. So I wouldn't put it past yours to overlook missing cats (or especially gutted cats as someone else mentioned). Is the car louder than it seems like it should be? It'd definitely be louder with gutted/missing cats.

I have to get the NSX smogged here in CA every 2 years. Always a struggle. The smog place that I use is just too close - approximately 5 miles. I have found that you really need to warm up the car (thoroughly) before the check. I've got headers - so perhaps the lack of cast iron manifolds lengthens the warm-up process. Anyway, once warm it passes with flying colors.
The smog place that I use is just too close - approximately 5 miles.

Mine's even closer, but local streets. I drive a few miles out of the way and drive there in the lowest gear possible (highest revs) to help it warm up.
Maybe you had the same thing I did.

When I got it smogged they put down the WRONG Car.. so check the vehicle information sheet to make sure it says 6cyl not 4 cyl NSX not NX.. NX = Nissan. (that is what I got)

Also list your readings and where you failed

CO2 NO ect.

'92 Sebring Silver NSX #181
This "gross polluter" disease may be spreading... I took my '94 in<sup>1</sup> for an oil change and smogging, and it, too, failed! The tech<sup>2</sup> said that in the 10 years he's been working on NSXen, this was only the *third* that didn't pass, and the other two were heavily modified (mine is bone-stock).

The car's still there -- they don't know what's wrong with it

-Bob ('94 NSX, but driving a '99 loaner Integra right now)

1. Los Gatos Acura
2. Gary