A catalyst deterioration detection system comprising: a pre-catalytic converter gas sensor; a post-catalytic converter gas sensor; a catalyst within an exhaust path; wherein the pre-catalytic converter gas sensor is disposed within the exhaust path upstream of the catalyst and the post-catalytic converter gas sensor is disposed within the exhaust path downstream of the catalyst; at least one computing device in communication with the pre-catalytic converter and post-catalytic converter gas sensors (120,130), the at least one computing device configured to monitor catalyst deterioration by performing actions including: estimating a catalyst gas storage level by comparing a difference between a pre-catalytic converter gas level from the pre-catalytic converter gas sensor and a post-catalytic converter gas level from the post-catalytic converter gas sensor; comparing the estimated catalyst gas storage level to a baseline catalyst gas storage level; and determining that the catalyst is deteriorated in response to the baseline catalyst gas storage level exceeding the estimated gas storage level by a threshold difference; wherein the at least one computing device is further configured to perform processes including: providing an instruction to a control unit to adapt an air flow ratio of an engine in response to the determination that the catalyst is deteriorated, wherein the catalyst deterioration detection system is a three-way catalytic converter system for use with a three-way catalytic converter, wherein the pre-catalytic converter gas sensor includes an oxygen sensor and the post-catalytic converter gas sensor includes an oxygen sensor, wherein the pre-catalytic converter gas level includes a pre-catalytic converter oxygen level, wherein the post-catalytic converter gas level includes a post-catalytic converter oxygen level, wherein the estimated catalyst gas storage level includes an estimated catalyst oxygen storage level, and wherein the baseline catalyst gas storage level includes a baseline catalyst oxygen storage level; and wherein the at least one computing device is further configured to perform actions including: estimating a carbon monoxide emissions level based on the estimated catalyst oxygen storage level; and wherein the determining that the catalyst is deteriorated is performed in response to both the reference catalyst oxygen storage level exceeding the baseline catalyst oxygen storage level by a threshold difference and the estimated CO emissions level exceeding a reference CO emissions level by a second threshold difference. a pre-catalytic converter gas sensor; a post-catalytic converter gas sensor; a catalyst within an exhaust path; wherein the pre-catalytic converter gas sensor is disposed within the exhaust path upstream of the catalyst and the post-catalytic converter gas sensor is disposed within the exhaust path downstream of the catalyst; at least one computing device in communication with the pre-catalytic converter and post-catalytic converter gas sensors (120,130), the at least one computing device configured to monitor catalyst deterioration by performing actions including: estimating a catalyst gas storage level by comparing a difference between a pre-catalytic converter gas level from the pre-catalytic converter gas sensor and a post-catalytic converter gas level from the post-catalytic converter gas sensor; comparing the estimated catalyst gas storage level to a baseline catalyst gas storage level; and determining that the catalyst is deteriorated in response to the baseline catalyst gas storage level exceeding the estimated gas storage level by a threshold difference; estimating a catalyst gas storage level by comparing a difference between a pre-catalytic converter gas level from the pre-catalytic converter gas sensor and a post-catalytic converter gas level from the post-catalytic converter gas sensor; comparing the estimated catalyst gas storage level to a baseline catalyst gas storage level; and determining that the catalyst is deteriorated in response to the baseline catalyst gas storage level exceeding the estimated gas storage level by a threshold difference; providing an instruction to a control unit to adapt an air flow ratio of an engine in response to the determination that the catalyst is deteriorated, wherein the catalyst deterioration detection system is a three-way catalytic converter system for use with a three-way catalytic converter, wherein the pre-catalytic converter gas sensor includes an oxygen sensor and the post-catalytic converter gas sensor includes an oxygen sensor, wherein the pre-catalytic converter gas level includes a pre-catalytic converter oxygen level, wherein the post-catalytic converter gas level includes a post-catalytic converter oxygen level, wherein the estimated catalyst gas storage level includes an estimated catalyst oxygen storage level, and wherein the baseline catalyst gas storage level includes a baseline catalyst oxygen storage level; and estimating a carbon monoxide emissions level based on the estimated catalyst oxygen storage level; and wherein the determining that the catalyst is deteriorated is performed in response to both the reference catalyst oxygen storage level exceeding the baseline catalyst oxygen storage level by a threshold difference and the estimated CO emissions level exceeding a reference CO emissions level by a second threshold difference.