I just bought a 2010 Dodge Grand Caravan. Took it through DMV and it failed because the Catalyst and O2 sensor where in a "Not Ready" status. I'm going to try everything previously posted. Thanks for all the info!

 

Not sure on the Caravan, but a series of cold starts are likely in order. About 5 of them. Drive to reach normal op temp, shut off to let cool down, start and drive again, etc. The status should changed to ready, or it will cause another failed test due to problems.

SJ03

 

I lucked out and didn't need to go to the extreme of replacing the O2 sensors. A few good drive cycles and the sensors were ready. Passed inspection okay. It does take close to 300 miles to clear. Highway and city driving did the trick. Thanks for all the info.