Well I went and smogged my car today. The first time he put it on the machine the car failed, he then let idle for a few minutes before trying again and I barely passed the second time around. These are my results

At 15 mph: PASSED
%CO2 Meas = 14.53
%O2 Meas = 0.29
HC (PPM) MAX 51, AVE: 9, MEAS 12
CO (%) MAX: 0.48 , AVE: 0.02, MEAS 0.05
NO (PPM) MAX 419, AVE 57, MEAS 418

At 25 mph: PASSED
%CO2 meas = 14.50
%O2 meas = 0.21
HC (PPM) MAX 35, AVE: 7, MEAS 11
CO (%) MAX: .46, AVE: 0.03, MEAS 0.04
NO (PPM) MAX 706, AVE 50, MEAS 394

Any guesses why I got 418 NO (PPM) at 15MPH?

This is all the stuff Ive done to the motor
- K&N Air Filter
- Whisper Carbon Fiber Intake Lid
- Smooth Intake Bellow
- Ported and Polished Throttle Body
- MSD Wires
- NGK TR55 Spark Plugs
- 3" Exhaust Cutout
- Magnaflow Exhaust
- LS7 Lifters
- Comp Cams LSX Chromemoly Hardened 7.400" Pushrods

 

Wow, i would of thought you passed with no problem, I have Mid length headers and catted Y with bolt ons, pretty much the same as you and had no problems, I failed the Visual but i only did it to get base decals. Could you need a tune??

 

in jersey the speed they bring the car up to is about 30 mph. although your car is spewing some crap. tune up, tune, some kind of internal engine cleaner.

 

I'm so glad Oklahoma doesn't have smog test

 

A few things I always do, Good grade of gas (Chevron), change the oil and make sure the Cat is as hot as you can get then. I drive in a lower gear on the way to the testers shop to keep the RPM higher to assist in heating up the Cat's. Might check your O2's.

 

Converters may have some age on them...

 

I only use 91 from Chevron and I have close to 107k miles on the car

 

converters most likely then.

 

If the O2 Sensors have not been replace. It might be a good idea also...

 

My front 02 sesors are fine and my rear 02 sensors have been deleted. So if my cats are bad I will not know since my rear 02 are deleted

 

Next time use seafoam before you go. That will clean alot of crap out of the car and get that cat hot as the others have said.

 

Your motor is basically stock, running on a factory tune correct ?

Why are you using ngk 55's ? Isn't that a cooler plug used in higer compression motors to help prevent pre Detonation ?? Correct me if I'm wrong.... Get her tuned to make sure you aren't running pig rich too. A ported tb could be part of the problem too since its untuned. Just my 2 cents. Good luck !!!

 

Cats are going bad! 14.5 co2 is perfect, and the .21 o2 means the burn was complete leaving very little o2 behind. Any codes like p0430 p0420 ever come on?

 

Its not the p/p throttle body cause I have been running that for a good 5 years. NGK TR55 is what a lot of people on here reccommend and I have never had a problem with them before. I believe the NGK TR6 is used for fi and n02.

The only SES code I have had was P0174, but that was a good two months ago

 

Well I hope it all works out for ya.

 

I mean I passed the second time around so Im not worried about since I dont have to do it for another 2 years. Just wanted to know what people thought of what made me fail the first time

 

What time of the day and what was the weather like, I know doing a test in the morning (cool air) will help as compared to as on a hot day or in the later afternoon.