I am lucky and don't have the tailpipe test in my county, just the visual inspection. I always read the emission posts for some reason. I have read that changing the oil and running the Jeep at hiway speeds for 20-30 minutes will help. I assume this gets the catalytic converter real hot to burn more off. I would also try some of the fuel additive that says it will help pass the inspection. I think Amsoil makes one. I dont know if it works, but the right chemicals could help the ignition of fuel. The $50 handshake never hurts either(that is a joke, I would never recommend doing something unethical).