Thread: How long for OBD to be ready after clearing codes?

I am looking for some guidance. In Sept. my daughters '06 Grand Prix base had the check engine light on. Since DIC said check gas cap I took a new GM gas cap with me on the next visit. Car had DTC P0455 stored and pending. I replaced the gas cap and cleared the code doubting that would do it. The check engine light came back on. I drove back down (she is at college 140 mi away) on Sept. 20, the car had DTC P0455 again. I replaced the purge canister and solenoid (AC Delco parts 20941985 and 19257603). I then cleared the code and everything has been good. She has only driven home once since then so the car only has about 350 miles on it since then and I have no idea on how many ignition cycles. When we went for IL emissions test the car failed as the OBD was not ready yet, this was after ~3 weeks. After 7 weeks my Innova 31703 scanner still shows the CAT and EVA systems as flashing so the yellow light is lit indicating the system is not ready for test yet. There are no DTCs pending or stored. Does anyone know how many miles or ignition cycles that are needed to get these OBD systems to show "Ready". I would really like to have the emissions test done when she is home for Thanksgiving as the registration needs renewal in December and I have to pass the test first.

Thanks in advance for your time.

@Scottydoggs - not in IL..... you don't need to have a code stored or pending. If any system is not ready you fail. If you fail twice you need to bring in receipt from certified mechanic... I don't want to fail a second time and worry about it.

@Scottydoggs - I don't think pulling the battery will do it as the emissions check also wants to very how long since a reset or clearing of codes.

@billboost37 - thanks I will have to run through the cycle when she comes home. After driving home 140 miles x two and all her local trips the only one that I can see not being done is a casual deceleration without touching the brake.

After 2 months and 950 miles the Cat and Evap still not ready. Had to take it to dealer for keyhole plugs so have them looking at it. They say the conditions indicated a P0442 (small evap leak) should be setting but is not. They are diagnosing, will post what they find. Then a RR wheel hub once it gets back home.

sorry for thread hijack OP, but I would like to ask BillBoost37 if he knows why the Autotap software is no longer available for sale. I have it and a couple years ago used it to help my brother with one if his cars, he went to go purchase and it was no longer for sale. Did a competitor buy them out and kill it off or something? Just wondering if you might know.

Google search "GM drive cycle" . The vehicle needs to complete and pass two full drive cycles without fault after codes have been cleared to become "ready"
There is a list of things to do and way to drive to help your vehicle complete the two full drive cycles quicker.