Mechanics

TC PO442 HOW DO I DO A DRIVE CYCLE AND COLD START

2003 Chevrolet Silverado

I had a check engine light and trouble code PO 442. Replaced the charcoal cannister, purge solonoid, and gas cap. I cleared the check engine light and troublecode with my code reader. I took it to the chev dealer and had the evap nitro smoke test done on it. They said it was working proper and sealing good. They told me it would take several cold starts to make the vapor IM sensor go from incomplete to OK. They said I would have to perform several drive cycles to get cat IM sensor to do the same. My question is exactly what does a cold start consist of and what makes a complete drive cycle for 2003 4.8 V8 silverado?
Thanks Robert C. Lowry @ letseelc@aol. Com
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Robertlowry
January 3, 2012.




So the code is gone and hasnt come back and there are no other codes set?I need to know that before answering your question.


Saturntech9
Jan 3, 2012.
That is correct. The code hasnt come back and no new codes have been set. I am however trying to get the Evap System Monitor to reset. It is showing incomplete. The Chev dealer told me I need to do cold starts and drive cycles to get it to reset.
Thanks Robert C. Lowry


Tiny
Robertlowry
Jan 4, 2012.
Forgot to ask you what size engine do you have?


Saturntech9
Jan 4, 2012.
4.8 V8


Tiny
Robertlowry
Jan 4, 2012.
I posted the drive cycle to reset all the monitors.


Saturntech9
Jan 4, 2012.
Does your code reader show if the monitors are ready or complete?The evap one sometimes takes a little while to set the monitors. Are you trying to smog the truck?
AD


Saturntech9
Jan 4, 2012.
Thank you I will try my luck.
Robert C. Lowry


Tiny
Robertlowry
Jan 4, 2012.
Yes I am trying to get it smogged. It has passed the emissions test and was failed on the evap system.


Tiny
Robertlowry
Jan 4, 2012.
Alright it usually takes a few trys doing the drive cycle its better if you have a scan tool that can check to see if the monitors are set. Let me know how you make out.


Saturntech9
Jan 4, 2012.
My scan tool tells me if my I/M monitors are set. I have the one to go. Thanks I will let you know how I come out.


Tiny
Robertlowry
Jan 4, 2012.

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