SENSOR O2 ท่อทดสอบออกซิเจนเซนเซอร์ Extender M 18x1 . 5

these are neeeded when using a hho system or a test pipe. they are also used to lean out your vehicle for better gas mileage. they are very easy to install by unscrewing your O2 sensor from your exhaust then screw your sensor into the extender and the