OBD2 since dtcs cleared vs since last drive cycle?

All my motors show ok/ready in “since dcts cleared” but some are not ready in “since last drive cycle”. Would I fail the emissions test again because they are not ready in “since last drive cycle”?

I have done the drive cycle twice and driving more. I replaced b1s2 oxygen sensor, cleared the code, did drive cycles and it shows ok in since dcts cleared but not ready in since last drive cycle.

Some states allow one readiness monitor not to be set and the vehicle will pass the emission test.

If more than one readiness monitor hasn’t set, the vehicle will fail the emission test.


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“since dcts cleared” and “since last drive cycle” are both under the I/M Readiness section of the scanner. Are monitors that are not ready in the “since last drive cycle” there because a drive cycle did not complete or is that for the last completed drive cycle? One menu in the readiness section is saying everything is ok the other is saying they are incomplete.

Each time you start the engine begins a new drive cycle, the “Since last drive cycle” data won’t be used during an emissions test. It is the cumulative results that matter, the data since the memory has been cleared.


Thanks for the info. I passed this time.

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I looked everywhere for this information. 2 years later and it’s saved me so much trouble. Thanks.