Need a replacement O2 sensor for your AEM wideband gauge? Be careful, there are two sensors used.

AEM replacement wideband oxygen sensors

So, for many years, the industry standard wideband gauge, the AEM 30-4100 gauge used whats known as a Bosch LSU 4.2 connector o2 sensor.

After having problems with getting sensors, AEM moved to a LSU 4.9 connector o2 sensor. AEM then discontinued the 30-4100 gauge, and they reintroduced the exact same gauge but with new sensor as the 30-4110.

What this means, is that you need to be careful when ordering a replacement sensor, as there are two different sensors, and they are not interchangeable.
To determine which one you need, look at the connector on the end of the oxygen sensor. The connectors are quite different.
(LSU 4.2 used from roughly 2003-2014) (LSU 4.9 used from 2015 on). But, dont go by our years of service, please double check your connector.

Now, Modern Performance carries both replacement sensors. So, click on the connector diagram above to jump to our page, and choose the sensor you need.