1988 F150 4.9L 6 Cylinder - won't pass smog, Would fuel injection cleaning work?

Fuel injector cleaning might help. I have heard of some gas tank liquids that are supposed to help. New York doesn't check for smog... Are there any rules for checking smog on a 25 year old vehicle in your state? In NY they are considered vintage or antique and no longer required to conform to today's rules.

California is pretty tough, especially smog. I brought truck in from New Mexico. Needed to get it weighed, and smogged. I will try the fuel injection cleaning and gas treatments as well. thank you

Go to a referee. Calif has the Highway Patrol referee stations for just what you describe, a vehicle that won't pass at a "check only" shop, or what they are are smog inspector places that will pass/fail but do not do repairs. Then if you go to a smog and repair shop and they still won't pass it, then that's where the CHP referee comes in. It used to be, years ago, that a 20 year old vehicle did not have to be checked..not any more. Cars are also rated by the State with a "green rating" determining whether you have to smog it every 2 or 5 years

I'm having the same issue with mine now. Did the cleaning help? Or was it something else?