Thanks to all who helped. My friend replaced the high flow cat with a "real" cat, and he passed the smog on the first try. Thanks again to all!




My friends LT1 failed the CA smog test today. Here are his results.

http://i23.photobucket.com/albums/b372/bobgodd/smog.jpg



I'm no good with emissions, anybody have any ideas as to what would cause such high numbers?

The car has SLP headers, a working catalytic converter, and GMMG exhaust. It has approx 140,000 miles, and the only known issue, is that it takes a long time to start, about 5-10 seconds of cranking. All the AIR equipment is intact and hopefully working.

Thanks.

 

the high NOx (oxides of Nitrogen) indicates a possible malfunctioning EGR system

how do you know your cat is working??

ok, good tune up?
engine hot when checked?
good quality fuel?
clean air filter?
fresh oil change?
EVAP system working properly?

 

Did he ask the smog tech for opinions?

When I lived in CA I never had a car fail, but had a couple come close, and I found the smog techs were well educated and able to provide good advice on what the likely causes were. Especially at the test-only centers.


With failures across the board like that, my own uneducated opinion is that he needs to start with a basic tuneup, check fuel pressure, check O2 readings, etc.

 

If the cat and O2s are original, I would suspect that they may be ready for replacement
Was he running premium gas?
I use a test only smog shop where the techs are very knowledgeable and will be glad to give you an idea where to start looking for problems based on the numbers, similar to what Steve said.
My Jeep was blowing high nox numbers and it turned out it had a crack in the header that was causing it.

 

Since its high on all 3.... HC, CO and NOx, there's a good chance the cat(s) are deceased. If if was a problem of running rich, it would typically be high on HC and CO, and low on NOx, while running lean would push HC and CO down, and increase NOx.

 

It is possible the cat is bad. The O2 sensors are new as of two years ago. The cat is/was a high flow cat if I'm not mistaken, not a "normal' one.

We didn't ask the tech for any opinions because they looked pretty sleezy, and it was a test and repair station, and they looked out for blood.

How often do air pumps go bad?

 

Another vote here for cat replacement and check the EGR and AIR systems.
It's high all around so a new cat should help, but there my be other issues
to resolve. How is the car in general regarding plugs, wires, opti, etc? Any
exhaust leaks? Clean air filter? Check the basics.

Where are you located? The smog test facility I use is very good and the tech
will work with you. He worked with me to get me passed last year.

 

Well it's not my car anymore, it's belongs to my friend now who lives in Fresno. I live in San Diego.

As far as the basics.. The plugs and wires were replaced when I did the headers two years ago, along witht the fuel filter. The air filter might be dirty, I don't think my friend would clean it on his own. His opti was replaced within this last year, so I hope that is still good. There aren't any exhaust leaks, we personally replaced the header gaskets and retightened up everything just a couple months ago.


I have reason to believe that the AIR pump might be bad, but I can't really check it because I don't know how it works. When I put the headers on, the air pump was making a loud squeeling noise, so I unplugged the electrical connector and just let it chill for a while. About a year later after my friend took ownership, he had some work done by a local mechanic, who I'm pretty sure reconnected the air pump, because when we chceked it yesterday it was all hooked up. I think it may just be dead all together, but I don't live around the car so I can't find out, and my friend is a retard.

 

Air pump wont cause it to fail.. Sounds like the first place to start is to make sure the Cat is working. Re-test and then take it from there.

 

As no one has brought it up, I will. If the car take 5-10 seconds to start, Iwouldn't be surprised if there is something wrong that could be causing the high emissions readings and the hard starting.

 

clean the air filter?


so, It has a K&N?

clean the MAF

 

Yes, it has the K&N kit.

The long start is an issue that has stumped me for years... Even when warmed up, it takes way too long to start. The opti swap didn't help at all either.

 

When I had long starting issues with my car a new set of plugs solved the problem.

 

I don't doubt that at all, but I'm stuck. Since the begining of the starting issues, the plugs, wires, and opti have been replaced.

 

If it was last tuned 2 years ago, you should at a minimum, change the plugs, wires, fuel filter, and clean the K&N. Then check the readings on the O2 sensors. If they are old, it would not hurt to change them out also. Then check the EGR valve - with 140,000 it should be replaced. Also make sure you have a 195 deg thermostat as the warmer the engine runs the better.
Before you go for the test, make sure to drive the car for at least 30 minutes, preferably on the freeway to make sure the engine is fully up to temperature.