Emmissions "Not Ready" for test help:
 

I learned something very helpful recently.

When you disconnect the 12v battery, or use a scan tool to reset codes, you will get a "not ready" for emissions test signal, which in some states prohibits you from getting or renewing plates.

A mechanic or dealer will likely tell you to "just keep driving" until the system resets.
Here is what they don't tell you: There is a certain, exact, finite set of conditions that must be met. These parameters can varry by make and model.

DRIVING IS NOT THE SOLUTION!!!!

You can drive L.A to N.Y.C. and your car will still not be ready for an emissions test. It's a bit silly, but look it up for your car.

Amoug other things, for my Chevy Truck to clear the "not ready" signal I needed:

5 Hot to Cold to Hot cycles, cold being engine temp = ambient temp

Accelerate zero to 55 mph and hold it there for 5 minutes

Accelerate to 55 mph or greater at 75% throttle position or greater

The really hard parameter to clear was:
Starting at 50 mph or greater, coast to 10 mph or less WITHOUT BRAKING.

This is / was ridiculous to do without a dynomomter but it did work the very first time I tried it. I got the "Ready" signal in less than 5 days and with just 10 miles of driving. Saved a lot of gas, time, and frustration once I knew what I was doing.

The mechanic / dealer who tells you "just drive it around" is assuming you will hit all the parameters by chance, given enough time. But if you are due or past due for a license plate registration you don't have time.

-John

Re: Emmissions "Not Ready" for test help:
 

A cheap bluetooth OBD reader and Torque Pro Android app can display the DTC readiness.

Re: Emmissions "Not Ready" for test help:
 

Correct. I used a long time friend- my ScanGauge for this purpose; it will tell you "ready" or "not ready" but not what to do to get it ready.

One other "silly" component is your gas tank must be "greater than 25% full but less than 75% full" to pass the emissions readiness test. In a full size truck it can be 8 or 9 gallons to get down to that from full.
People get frustrated for not being able to pass an emissions test and it's often for simple, but unkown reasons to them. LOOK IT UP ONLINE.