too much co emissions

I got my 78 caprice smogged the other day and it failed the test (I live in California) so the tech told me my co emissions were too high I was like at a 2.20 he said they should be around 1 I asked him what the problem could be and alls he told me was it could be a number of different things sometimes the carburetor needs to be adjusted. And that's all he told me. So I wanted to get some more info on what could cause excessive co.

Unfortunately, he's right, it could be a number of things that cause high CO emissions. EGR valve removed or improperly functioning, carb adjustment (air-fuel mixture) and idle, catalytic converter, worn valves, worn piston rings, leaking valve guides, fouled spark plugs, ignition coil going bad, vacuum leak, any kind of misfire, and a number of other things I can't think of at the moment. With older cars, it really gets tricky to pass smog. Luckily for me, I live in a county that doesn't require smog and the ones that are nearby me that do, exempt cars that are over 25 years old which would exempt every car I own except one.

I would try a complete tune up and have the catalytic converter tested at a muffler shop as a start. Put a timing light on every single spark plug wire and watch the flashes if there's even a hint of erratic flash on one or multiple, then it's not firing smoothly.

Well I think I will need to adjust the carburetor the exhaust does kinda smell like fuel. I gave it a tune up and it ran alot better but not as it should. And ill have to try the muffler shop I didn't know they test out cats. Yea they say California is awesome but... It really isn't

Hey man, yes everything solo said is right on point, with older cars it gets harder. But the three things possibly four things id check right away would be ofcourse the carb tuning, egr valve, and make sure it has a 195 degree thermostat, lots of people like to put cooler thermostats in, and the engine runs cooler which puts out more emissions, gm designed it with a 195 thermostat so it will run hotter for less emissions and fuel economy, and lastly ignition timing, i dont think it contributes much with emissions, but if the cars running in top shape the emissions should be right with it. I would advance the time to about 12 degrees at idle, dont set it at 6 degrees like it says on the sticker, if your sticker is still there. If its not set at 10 or 12 degrees already, youll notice a little performance gain and a tad bit more fuel economy. Let us know how it goes!

For once I'm glad to live in NY. Vehicles over 25yo don't get emission tested.

Ok right on. My egr is new my tune up is done carb adjustment is next on my list. I'm not sure what thermostat is in it or if it even has one for that matter so ill have to check it or replace it for peace of mind on that part. I dont have a timing gun so ill have to get my hands on one so I can check my timing I wouldn't be surprised if its off

May sound silly but if your cat is glowing orange, change that out. Get it running hot after dark and take a peek at it.

Ask me how I know,
Hugh

Hmm actually I haven't tried that. My battery died so I gotta fix that first. Well I took a peek under the car and it seems to have an aftermarket weld on cat I have no idea if its the right one or not though

so I saw that my car was running too cold, I added an aftermarket gauge so I can see how hot/cold its running and it was running at about 160 so it was way too cold. so today I put a new thermostat (an OE temp one). so when I took the old one off I looked at the bulb and it said 160 so obviously it was the wrong thermostat. so now with the new thermostat its ruuning better and the exhaust doesn't smell that much anymore

I can't believe they make older cars in California pass emissions like said Sweet said even in NY we aren't that anal.

They don't even car if you have a converter on car from the 70s I've passed without one before.

Anyway make sure your advance vacuum hose is in the ported not manifold it will lower emissions. GM designed it like that

from the factory it hurts power and mpg but lowers emissions. Check all you vacuum hoses one small leak and your

emissions would be in the toilet.

yea they say that CA is the greatest state but I say no cuz these smog laws have us by the throat! I hear there's areas that don't have smog laws but I have a hard time believing that. I gotta get a diagram so I can see where all the vacuum hoses go. my vacuum advance hose is hooked up to the lower driver side of the carb that's correct right?

yea they say that CA is the greatest state but I say no cuz these smog laws have us by the throat! I hear there's areas that don't have smog laws but I have a hard time believing that. I gotta get a diagram so I can see where all the vacuum hoses go. my vacuum advance hose is hooked up to the lower driver side of the carb that's correct right?

Yeah the driver side lower should be the timed vacuum port either that or from factory  it connects to a tvs tree routing

which is a headache. One reason I have always preferred older cars is all I need is a safety inspection and the older the car

the more likely they cut you slack anyway. (Usually only on stuff like the ebrake though not safety items). Now in NY

if it was a post 96' car you had better have it in order. I have had to bring cars back two or three times for stupid crap.

Oh dang that's crazy man. Yea I just wish these smog laws weren't so strict tho. I think I gotta rebuild the carburetor it kinda stalls and doesn't move when you floor it