[HOUTX1LE]

Hey guys kind of stuck here. Had battery replaced a couple weeks ago and I state inspection is up. Took it in it failed, for a couple sensors not being ready. Put about 100 miles on it and still failed. Do you guys know how long of a drive cycle is needed on these cars for the sensors to be ready?
Thanks in advance.

[Hick]

It varies on multiple factors such as electrical load, miles, start/stops, even AC on or off.


Your best bet is to get a cheap OBDII bluetooth scanner and download the free app torque. It has a readyness test built in. Or continue to drive around under varying conditions and hit up Autozone to check before going back.


Good luck!

[ember1205]

It isn't really "how long of a drive cycle" as much as it is "how many drive cycles" are necessary to get the sensors to a ready state. As mentioned, a cheap OBD II of your own or possible leveraging one from Autozone or similar. You should also be able to go back to the place the did the battery swap and have them check the sensor ready state.

In CT, I believe you can have only one sensor in a not ready state (if any) or you'll immediately fail so I understand the issue. Where are you located, by the way?

[Mark114]

I found this on the internet. I don’t know if it is accurate but give it a try.

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

[HOUTX1LE]

Thanks for all the info guys. I am in Texas I believe only one can fail to be able too pass. I will try the drive cycle tomorrow.

[GroundhogSS]

I had the same problem two weeks ago, also in Texas. I finally got it down to only one not ready and passed. I use the Torque app to monitor it.

[HOUTX1LE]

Thanks for all the input guys, I plugged in my OBD2 reader and monitored the sensors until they were all ready. Took about 120 miles of driving and 5 drive cycles for all sensors to be ready to pass inspection.

[SSport16]

Also try running the fuel gas close to empty then fill up completely. I had the same issue about 7 months for my state inspection. Did everything from driving 30 miles or so on the interstate at a constant speed to letting it idle for 30 mins, nothing until I emptied the tank and filled up. Checked with a cheap ODBII reader I bought, fuel sensor then showed ready. 2 others were not, but in NC a max of 2 can show to be not ready and still pass. I would definitely check on your own the sensor readiness before bringing it in again to be inspected. The guy at my dealership was cool, he would also check with his reader before putting it on the machine and show up as a fail.