The mechanic told me which O2 is bad on a 2000 Boxster. He reset the check engine light. I changed the sensor. However he said there is some sequence that you have to follow in order to reset an internal code. Otherwise the car will fail the OBDII check. I found something here: http://www.systemsc.com/codes.htm
* Monitored & Set During Three Cycles; Warm-up, Driving, & Trip
Warm-up Cycle - SAI, EVAP, (from cold start to operating temperature, 2 min. minimum)
Driving Cycle - O2 Sensors/Heating, TWC, TRIM, (2 min. idle, 5 min. drive, 2 min. idle)
Trip Cycle - Diagnosis of All ECM Systems, (2nd Driving Cycle after shut-down, 20 min. max.).
Is this correct? Anyone have any luck with this procedure? I don't understand the exact sequence.... is it:
cold start 2min idle
2 min idle
5 min drive
2 min idle
shutdown
2min idle
5 min drive
2min idle
am i right? thanks!
Full Version: OT: Boxster O2 sensor change
To pass an OBD2 test the "readiness code" has to be set. This shows that that all the emission systems are working. When the light is turned off (fault memory cleared) the readiness code must be created from the beginning. Some of the systems (evap & secondary air) only come on and self test from a cold start. There are a procedures to set the code but generally a few days of normal driving will do it. The code would have reset faster on its own if you had just changed the sensor and waited for the CEL to go off.
QUOTE(ejm @ May 21 2006, 07:54 PM) 
To pass an OBD2 test the "readiness code" has to be set. This shows that that all the emission systems are working. When the light is turned off (fault memory cleared) the readiness code must be created from the beginning. Some of the systems (evap & secondary air) only come on and self test from a cold start. There are a procedures to set the code but generally a few days of normal driving will do it. The code would have reset faster on its own if you had just changed the sensor and waited for the CEL to go off.
So can I assume that a few days of driving will reset it? I really won't know till I try to get the car inspected. Thanks for the info.
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