Failed SMOG. Too high NO and HC??
 

I just took my car to the smog shop today and I failed the
-NO (PPM) 15mph Mine read:1952 and max is 487 @25mph
-NO (PPM) 25mph READ: 1811 max: 774 @ 25mph
-HC (PPM) 15mph read: 116 max: 66
-HC (PPM) 25mph read: 27 max: 49

Could anyone please help me figure out what's wrong? Or why they measured like this.

my car is 1999 honda civic si
b16a from japan
5 speed
110,000 miles

Re: Failed SMOG. Too high NO and HC??
 

Put a working cat on it if it doesn't have one.

If the car has an EGR, clean/replace it. Also check timing and AFR. Running lean increases combustion temp. High combustion temps produce NOx pollution.

Re: Failed SMOG. Too high NO and HC??
 

What's an AFR bro? I'll be checking the EGR valve this weekend and timing. Thanks

Re: Failed SMOG. Too high NO and HC??
 

air fuel ratio

Re: Failed SMOG. Too high NO and HC??
 

For sure man, thanks for the help.

Re: Failed SMOG. Too high NO and HC??
 

this car does not have an egr. From the looks of those numbers you might need a cat. Post up the other readings such as the o2,co and co2 so I can get a better idea of what might be needed.

Re: Failed SMOG. Too high NO and HC??
 

hey guys, hope I'm not thread jacking but I'm running into something similar here are my numbers

1992 Honda Prelude 2.3si



Luckily I saved my test from two years ago

Test from 06/2010 - only thing changed after the test was on 11/2011 the distributor, and a few screws on my gas tank (also had a stock filter on in 2010, 2012 I have KN reusable cone filter)


2010 test - pass

http://i1131.photobucket.com/albums/...0smogtest2.jpg



2012 test - failed

http://i1131.photobucket.com/albums/...2smogtest2.jpg


My 2012 results are so high compared to my 2010 tests. Any ideas, the guy says my timing looks off. Do I need to advance the timing on my car? Would that only fix one of those? Should I run any fuel cleaner or seafoam in the tank, suck some seafoam through the brake booster? Thanks for advice.

Re: Failed SMOG. Too high NO and HC??
 

Hey guys. Not trying to jack this issues but i also have the same problem as the guy posted.

My NO is above 120 which needs to be below or at 120.

Does anyone know what i need to do?

Re: Failed SMOG. Too high NO and HC??
 

Yeah, reduce the NOx content of the exhaust.

Seriously though, you bumped a 2 year old thread for that? Provide all the numbers from the smog check, the year and model of car, and what mods if any, and maybe someone will have a better answer.