ER Spec O2 Sensor Adapter for your Nissan SR20DET. Have a Megan Racing or GReddy turbine outlet and don't want to buy a new O2 sensor because yours won't fit? This adapter enables the use of the skinny-type O2 in the larger fat-type whole. No need to go searching for that other O2 sensor when using aftermarket turbine outlet. Adapter can also be used as block-off. Picture to show different angles.
