Hey guys, I've been reding and replying for a while now and usually can find the answers by searching but am not finding anything to help this time. I have an 01 1500 4X4 RC with the 5.2 that needs the emissions sticker for my county here in PA. As luck would have it the #7 plug burned the electrode off and threw a code/check engine light. So I put in new plugs and had the code cleared but the emissions tester is telling me that the computer hasn't cleared or reset everything for it to pass the test. I have put almost 150 miles on it over 3 days with no check engine light but it stiill won't pass. My question is how long or how many miles does it usually take for the computer to clear/reset for passing the emissions test. Thanks for any info.

 

i'm sure sure, but you are probably getting close. when i was fighting evap related codes, it used to take about 3 days for my CEL to come back on.

do a search on - drive cycle for some similar threads.

 

Have you tryed to reset the pcm ny unplugging the negative battery cable for about two minutes then hooking it back up?

 

You might not want to pull that cable just yet, your PCM is logging cycles since it was last cleared, pulling the battery is going to make it start counting all oever again. I had the same issue with an EVAP leak. Guy told me to just keep driving it and if everything is okay time is all it will take. Keep the receipt with you from the station saying it failed just in case you get pulled over

 

so on some things you reset the pcm by unplugging the negative battery cable, than on others you just drive it for a certain amount of miles??? if so how do you know when to do the appropriate manner???

 

Either way you do it, you still need to log those drive cycle's. I think it's a combination of miles driven and key starts.

 

no.

resetting pcm is always accomplished by removing negative battery cable and turning on headlights for 30 seconds. this clears all memory including drive cycles and logs, and learned tunings, etc and reloads factory defaults - which should make it run about right but maybe a tad rich. this event makes your car "not ready" for emissions testing.

driving a certain amount of cycles and miles and days will build log history in the pcm, allow it to monitor the systems, allow it to adjust tuning parameters, etc. these logs are used by emissions testing to PROVE that the measured O2 readings are stable, and that the pcm is satisfied with the results, and that the CEL is not on, and the evap system has worked correctly for several days.

 

Oh I get it. Thanks for the responses

 

Thanks for the responses and for the interesting explanation. Four days and 200 miles= passed the inspection!

 

Allright, good for another 12 months