[gpjlytham]

Hi All.

I bought a Sky 2.4L with a bad catalytic converter, it was clogged and the check engine light was on. To register the car in my name I had to take it through emissions so I replaced the Cat and turned the CEL out using my scan tool. when you turn out the CEL you have to go through a driving cycle so that the computer can check all the emissions items and they go from inc to ok on my scan tool. I assume inc is inconclusive and you have to drive until each item goes to ok.

The problem: - I drove approx. 250 miles attempting to include all driving styles but the evap system monitoring wouldn't go from inc to ok. I decided to take it through emissions with it still in "inc" mode and the car passed AZ emissions.

So the reason for this post is that the evap systems monitoring doesn't have to be "ok" to pass emissions in Arizona. I have no idea if that is the case in other states but it is worth trying in any state.

 

[rjgramps]

Hi All.

I bought a Sky 2.4L with a bad catalytic converter, it was clogged and the check engine light was on. To register the car in my name I had to take it through emissions so I replaced the Cat and turned the CEL out using my scan tool. when you turn out the CEL you have to go through a driving cycle so that the computer can check all the emissions items and they go from inc to ok on my scan tool. I assume inc is inconclusive and you have to drive until each item goes to ok.

The problem: - I drove approx. 250 miles attempting to include all driving styles but the evap system monitoring wouldn't go from inc to ok. I decided to take it through emissions with it still in "inc" mode and the car passed AZ emissions.

So the reason for this post is that the evap systems monitoring doesn't have to be "ok" to pass emissions in Arizona. I have no idea if that is the case in other states but it is worth trying in any state.

Interesting experience you had there.

I wonder if you disconnected the battery for a time, if that would clear "inc".

 

[JohnWR]

This is the "official" GM drive cycle as posted on obdii.com:

General Motors Driving Cycle
A complete driving cycle should perform diagnostics on all systems. A complete driving cycle can be done in under fifteen minutes.

To perform an OBDII Driving cycle do the following:

Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run.

Idle. The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater, Passive Air, Purge "No Flow", Misfire and if closed loop is achieved, Fuel Trim.

Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until 88km/hr (55mph) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.

Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed.

Decelerate. Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 32km/hr (20 mph). During this time the EGR, Purge and Fuel Trim diagnostics will be performed.

Accelerate. Accelerate at 3/4 throttle until 88-96 km/hr (55-60mph). This will perform the same diagnostics as in step 3.

Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst.

Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.

Reprinted on OBDII web site courtesy of General Motors Corporation

© General Motors Corporation

The key thing is not the distance driven, but hitting all of the "buttons" needed to test all of the functions.

 

[gpjlytham]

This is the "official" GM drive cycle as posted on obdii.com:



The key thing is not the distance driven, but hitting all of the "buttons" needed to test all of the functions.

I had a copy of that and I think i did all the things stated. I also found other drive cycles and tried some additional things but the evap system never went to ok?

55mph for three minuites is chalenging/danger mouse. The freeway close to me has a 55 mph limit while they are doing construction and I was the only vehicle doing 55, evryone was flying past me.

 

[splitrimz1]

FYI: May 15, 2019 · The US Environmental Protection Agency (EPA) guidelines allow up to two monitors to be in a “not ready” state for model year 1996 through 2000 vehicles and one monitor “not ready” for 2001 or newer model year vehicles.

The Evap monitor is the toughest one to get "ready".