What are the drive cycle requirements for a 2002 Pontiac Gran Prix with the 3.8 normally asperated engine? I did a great tune up .Im getting 25.6 MPG. But the Evap and Cat codes wont clear says the smog guy.No check engine light on now since the new cat converter was installed.I found the Evap vacum leak.All new GM plugs and wires were installed. All New O2 sensors installed. I drove the car a little over 100 miles already.Drive it ..more? How? What speeds? ..to clear all and smog it ? What'* the trick? It'* geting frustrating after all this work and expense. Still smiling

Take a look at this.

https://www.gmforum.com/specifications-general-information-132/how-set-readiness-emissions-296020/

Thank You ! ..very much.

moved to it'* proper Mechanical Section. General Chat is for items that affect all platforms and "General Chat". It really helps the GearHeads, others with ownership of same/similar Models, the Forum regarding search bots, and our own internal search engine when we keep things in order. Thanx.