Just bought a 85 f250 for my boy that just got back from the army and had to smog it thanks to Ca emissions laws. But it won't pass smog due to gross carbon emissions of 946, I'm only allowed 250 any ideas on how to cut that number down?

 

Is all the emission equipment still intact?

 

I suggest you read,you should have received a current smog certificate with the purchase of the truck.
https://www.dmv.org/

 

That's a private site, the state site will be https://www.dmv.ca.gov/portal/dmv/detail/vr/newvehicle

And yes, the seller is responsible for smog, so if you can catch him you can put it back on him.

But you mention a high carbon emission. Do you mean CO, carbon monoxide?

What are your Nox and HC numbers?

If you have good numbers for Nox and HC, then high CO numbers usually mean a dead cat. And in CA, that means a new OEM or, if you are really lucky, an approved aftermarket. But first, the numbers please unless you can tackle the seller.

 

All the smog equipment is still intact. But I made the mistake of going off a smog cert from 5 months ago. So now I'm stuck with the problem unfortunately.

 

Numbers, including numbers from the old cert.

 

Common trick in California is to use e85 for the smog test. Doesn't work in vehicles with check engine lights but works in older ones. That's how I have to smog my 78 and 81. Brings the numbers well below limits.

 

If the OP doesn't have the actual numbers, maybe that would be his best bet, because it's not possible to figure out a fix unless you know all the numbers. If it smogged 5 months ago, I can't see the cat dying in that time, but then the number from 5 months ago vs. today might help.

 

Hc number is 945

 

You are not stuck with the problem. The seller is obligated by state law to provide a recent smog certificate, no exceptions. Five months old is not recent enough.

I would contact the seller and if he is unwilling to help you, take him to small claims court for the repair costs.

The law is super clear on this and on your side.

 

We need all the numbers and the ranges allowed. You can post a picture of the report if it's easier to do that. From the old smog cert and the new test. The idea is to compare the numbers and to look at the relationship between the numbers new and old.

If you are high on HC, that will make the CO go up. But without reference points--the old report and the stated limits for HC, it's more of a guessing game.

Re read some of this--if your HC is 945 and the limit is 250 you have a rich condition. You need to check the carb for proper adjustment including float level. Check for vacuum leaks. Do you have a miss? Even a slight miss or one that comes and goes. Clean filters and clean oil sometimes help, as the PCV fumes will help push up HC. Is your PCV functioning? How do the hoses look? A new PCV is cheap, add that to the mix. Do you have an air pump and is it working?