DIY Toyota EGR Valve Diagnostics - Back Pressure Modulated

The EGR system used on an 1994 toyota 4runner is the same as the camrys of the same vintage and it's a complex one. It's vacuum AND back pressure modulated and presents a good challenge for even the best shade tree mechanic. Here's how you diagnose the system. This video is for entertainment purposes only. 50sKid assumes no liability for any repairs or modifications performed by the viewer as a result of the information contained in this video.