Old cars, and we're talking really old here, had what was called a mixture control lever on the dash. Your car, the marvel of modern technology that it is, has a Saturn oxygen sensor that does the same basic thing. As it turns out, the Saturn oxygen sensor is smarter than you are, at least as far as sniffing exhaust goes, and does a better job at adjusting the mixture in your engine. Given what happens if you sniff exhaust, we're happy to let the Saturn oxygen sensor have the job. Like with most machines, your Saturn oxygen sensor isn't failure-proof, and the Saturn oxygen sensor will need to be replaced periodically. How often is partly up to you, and partly up to your Saturn oxygen sensor. Some manuals suggest replacing the Saturn oxygen sensor at certain intervals, while some recommend waiting until you experience a Saturn oxygen sensor failure before replacement. The latter can be dangerous to your catalytic converter, but the choice is between you and your Saturn O2 sensor. Either way, when Saturn oxygen sensor replacement time comes, order your new Saturn oxygen sensor from us. We offer the lowest prices on premium-quality Saturn oxygen sensors, and we'll ship it to you fast so you're not out of service any longer than you have to be.