Yes, your smog check mechanic is right. You do need to drive your Pontiac
for at least 2 weeks (normal everyday driving) for the emissions computer
"readiness flag" to set. What happened during the EGR valve or EGR system
problem is the readiness flag belonging to the EGR system was not set
because of the defective EGR sensor. Readiness flags are internal self tests
the emissions computer runs to ensure all emissions systems are functioning.
It's basically a self-test system. Now that the EGR sensor is replaced and
the emissions system is running properly, with the check engine light turned
off, the EGR self test will proceed and the proper readiness flag be set
"on". Normally two weeks of driving will fix this problem.
posted by SmogTips Support
