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My 2012 Toyota Corolla keeps failing emissions because the car was stored for a bit with battery disconnected. Guys says car computer history was erased. Drove 50 then 100 miles and still no. Don’t know what to do.
 

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My 2012 Toyota Corolla keeps failing emissions because the car was stored for a bit with battery disconnected. Guys says car computer history was erased. Drove 50 then 100 miles and still no. Don’t know what to do.
Curious...didn't smog person tell u what to do when yours failed test? Here, u would have to go to authorized smog repair shop. No idea on why "computer history erased" causes test to fail. ? Good luck on outcome.
 

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If you don't have scan tool to read error codes/monitor set info than best take it to repair shop for diagnosis.
They may well find that it just needs to be driven but they can pinpoint the monitors that are not setting.
 

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Scantools are $12. Buy one and it well tell you what cycles are complete. Read your state inspection rules. Proceed accordingly.

Sent from my Pixel 3a using Tapatalk
 

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Most likely, there are no DTC error codes. But you do need to drive it a while to get all the system checks to show "ready". The ones for the cat and evap systems are typically the slowest, and require some very specific drive cycles.

Good resource of info, here.
 
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When the battery is disconnected, the ECU goes into relearn mode. You need to give the ECU at least a day or so and performing some drive cycles in order for the ECU to record the inputs and is ready again.

Since California is the standard testing state these days, many states have adopted some of their practices for emission testing. They have a policy in California, if the CEL is on, they aren't allowed to test it.

When getting a vehicle tested for emissions, do the following. Plan ahead of time so that the vehicle is :

a) at operating temp
b) use a scan tool like BAFX and torque pro to verify all monitors are set to ready. In California only : you are allowed only evap monitor to not be ready for 2000 MY and newer.


c) no external leaks of coolant or oil. This is only applicable to California. Haven't experienced it here in Arizona yet, but never know. I just know that Arizona has adopted parts of the testing method.

d) verify your gas cap o ring for damage. Since they likely will do a pressure test on it.
 

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I am so happy that I don't have to deal with emission testing or inspections. What a complete PITA.
 

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When the battery is disconnected, the ECU goes into relearn mode. You need to give the ECU at least a day or so and performing some drive cycles in order for the ECU to record the inputs and is ready again.

Since California is the standard testing state these days, many states have adopted some of their practices for emission testing. They have a policy in California, if the CEL is on, they aren't allowed to test it.

When getting a vehicle tested for emissions, do the following. Plan ahead of time so that the vehicle is :

a) at operating temp
b) use a scan tool like BAFX and torque pro to verify all monitors are set to ready. In California only : you are allowed only evap monitor to not be ready for 2000 MY and newer.


c) no external leaks of coolant or oil. This is only applicable to California. Haven't experienced it here in Arizona yet, but never know. I just know that Arizona has adopted parts of the testing method.

d) verify your gas cap o ring for damage. Since they likely will do a pressure test on it.
Read the rules for your state. They're all different. Sometimes the CEL can be on.


Sent from my Pixel 3a using Tapatalk
 

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I mentioned California because I don't know where the op is from and I lived there before. Arizona uses this policy as well.

Arizona has adopted some of the practices that California uses in their smog testing procedures. I do not know if they will also adopt their program of aftermarket parts. Hope not.
 
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