I'm guessing your civic right?

Time for a "complete" tune up..
Plugs, Wires, Cap, Rotor Button, Fuel and Air filter.. Also make sure when you pull the plugs no oil is on them..
Normally I would use the scanner to check voltage on the O2, But since you don't have one just start with whats listed and see if the Cel for the O2 comes back.. If so replace it..

Later!!