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OBD system "not ready"

Uncle B

May 13, 2000
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City, State
Year, Model & Trim Level
'97 Expler XLT '01 Ranger
I was going to get my ST emissions tested and the check engine light came on. Come to find out the fuelcap was loose and it set the trouble code. I was able to erase the code with the use of a scanner and went on to the Inspection Station where it was rejected because the system was not ready. Can anybody tell me how long it will take to reset the system? (i.e. no. of start cycles or Run time)



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i think that it is at leat 3 key cycles

The key cycle would do the same thing as clearing the codes, which you have already done.

I have never heard of an OBD reading "Not Ready." How much had you driven it between clearing the codes, and getting the inspection? Maybe it needs to be driven a certain distance to re-learn .

I had only two key starts and drove it about 3 miles. I didn't think the system would have to relearn after clearing the code. It was at the emissions station where their equipment said the OBD was not ready. They said there may be problems not yet identified because the vehicle's system had not completed it's test. Their answer was to drive the vehicle under a variety of operating conditions. I was just wondering if anybody else had experienced this and how long it took. I need to get the testing done by the end of the month.



yep, i had the same problem. my O2 sensor went bad, and tried clearing the code and taking the test, but it wasn't ready. i my obd reader tells you which monitors are ready or not, so i was keeping an eye on them and they wouldn't reset. i found out that my car wasn't getting hot enough (i have a towing package with an oversized radiator), so i stuffed some cardboard in front of the radiator and they started to reset after driving for a couple days. in the owners manual they describe the drive cycle to reset the obd codes.

It's 10 or so miles, but it can vary. I think it's longer if you disconnect the battery than if you just clear the codes. Drive it a couple days and it should be fine, or check it again before bringing it in for inspection.