How to fix a nitrogen oxide problem?

My 95 Honda Accord got an emissions testing & the Nitrogen Oxide levels
were to high? How can I fix it cheap?

 

---------------------

Better details yield better answers.

What state / province, what have you tried so far, what's the MILEAGE,
what kind of gas do you use, has the car been serviced in any way,
lately, anything unusual happening with the way it runs otherwise, was
the car warmed up properly before the test, have you ever put fuel
injector cleaner in the fuel, is radiator reservoir full according to
the manual, ??????? Good start.

'Curly'

 

We need to see your numbers. Need your readings plus the limits in your
jurisdiction.

Also need what Curly is asking for in the other reply.

High NO is the product of excess combustion temperatures and/or a lean
mixture. Plugged EGR passages, a partially non-functional EGR valve, a
small exhaust leak ahead of the cat, excessively advanced ignition timing,
all these can cause high NO.