[rbarrero]

Hi - I recently had to replace the MAF on my 1999 RR 4.0 SE (Bosch) and the tech cleared the service engine soon light. Well, I didn't know that it had to go through a "readiness" or "drive cycle" before getting it smogged, so it failed today. I was told that until the computer can check these systems, the smog will fail no matter what.

My question is how long do I need to drive it for the system to check all the components and I can get re-tested?

Here are the 3 non-continuous monitors that were "not ready": Catalyst, Heated Catalyst and Oxygen Sensor.

Thanks,

Rafael

 

[TheoR]

I went through the same thing.

For me, it took me almost a week to get the OBD to be ready.

So, drive around for a week, and do it again.

Regards,

 

[Rich998a]

Are you sure the original problem was MAF and not something else like a HO2 sensor?

 

[rbarrero]

This was done right before I purchased the vehicle because the Service Engine Soon light went on a few days before I was able to pickup the car. The previous owner had it looked at by a tech and they replaced the MAF.

How do I test/check the HO2 sensor?

Thanks,

Rafael

 

[Rich998a]

Check using either Testbook or a Picoscope.

 

[Goatwerks]

Those OBDll monitors can take as many as 600 miles to go to ready state after clearing codes.
Best to do a few highway runs and some stop n go, if you have a good code checker, you can check the ready status of all OBDll monitors(cheepie $69 Matco code reader resetting tool works fine for this).