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Drive Cycle for Emission test help

45057 Views 16 Replies 6 Participants Last post by  Noodles
So I replaced the MAF on the 01 ML430, and have to get ready for the Smog test here in Ca.
Running it through the code reader, in the I/M readiness, 3 are still not ready yet: EVAP, Sec Air and EGR Sys. If more than one is not ready it wont pass. This is my second week driving it to work and back, its 16+ Mile commute and 20-60min drive.
Can anyone provide any advice on having the EVAP, Sec Air and EGR Sys sensors set?


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Keep in mind that these readiness monitors will not set if driven above 55 MPH. Varying speeds between 35-50mph are much better with stopping in between. The amount of miles you drive is not the important thing, but how you drive them.

Also pay attention to the note under para #7, as to the fuel level must not go below 1/4 or above 3/4, in order for the EVAP system to set.
changed MAF sensor
ive tried and have not set yet
will try more carefully this weekend
just need one more to get set, since it seems I can pass with 2
You have to get two ready. You can pass with only 1 not ready.
Please, update your profile with vehicle and location info.

In Texas 96-02 pass with two monitors not ready. '03 up only one.

If you have means to look at live data stream check STFT (Short Term Fuel Trim) and LTFT (Long Term Fuel Trim) values. LTFT needs to be less then 15%, STFT needs to hover +-3%. When monitors take that long to complete there is usually fault code just to pop up.

You have never fully answered question why computer was reset in the first place and what were the codes prior.
He replaced the MAF.
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