Using this Cobb MAP Sensor Adapter is a breeze. First, make sure your Subaru is one of the compatible models: 2002 - 2007 WRX, 2004 - 2021 STI, or 2004 - 2008 Forester XT. Then, find the throttle body in your engine. The adapter fits directly into it, so just use the included o - ring and hardware for a leak - free installation. After that, you can install your pressure sensor with the 1/8' NPT threads. When it comes to maintenance, keep it clean and dry. Check the o - ring regularly for any signs of wear and replace it if necessary. And always follow your vehicle's maintenance schedule for best results. Be careful not to overtighten the hardware during installation to avoid damaging the adapter or the throttle body.