Failed An Emissions


New member
My corolla has 45K miles and on Sat it failed an emission. Here are the emissions failed results; any ideas to resolve the issue will help. The first time it failed and I was been told by dealer to drive on highway above 65m/hr for 20 min and it should resolve the issue; but it didn't help and my emission failed second time.



Any suggestion is appreciated.



04 Corolla CE 5spd
You mean 145k miles on your 1999 Corolla automatic?

Was your battery or ECU disconnected recently? Original oxygen sensors?

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New member
Dom, Thanks for quick response.

My 1999 corolla runs like brand new with 140 K miles

This car belongs to my friend. Car has only 45K miles and it's 2010 model. I am sure it's original oxygen sensor. He said nothing as been disconnected. Recently he has replaced all four tires.



I know Karate, Kung Fu, and 47 other dangerous wor
Sensors that indicate "not ready" - means that he has to drive a bit more to trigger enough drive cycles to set those sensors. This is part of the I/M readiness system - most places do a quick I/M readiness check for emissions, meaning they plug in a scanner and verify that the I/M readiness sensors are all set to "ready". If any come back as "not ready" or failed (ie, check engine light or pending DTC) - then you automatically fail emissions testing.

Has he recently scanned the ECM, reset a CEL? Disconnected the battery for any reason? Did any electrical work, replaced any fuses, relays?

Basically he has to drive around until those sensors do a self-check. Could be a couple of miles, could be a couple of hundred miles. All boils down to drive cycles - the number of cold starts, cruising speed, duration of run time, etc.

A little weird that it is just these particular sensors that are not set to ready, for this year and mileage - catalytic converter should be fine. Oxygen sensor - upstream (pre-cat) is an AFR type sensor, the downstream (post-cat) is a conventional O2 sensor. At this mileage, should not have gone bad, possible it is a wiring issue. But in any of those cases, it would have flagged a DTC or popped on a check engine light.



New member
Thanks to both of you (Fishexpo and Dom),

Going to call Costco to find if battery was disconnected during tire change.

Will take all suggestions to drive another couple hundred miles with different drive cycles.

Dom, thanks for the link; great article on OBD Readiness Monitors


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