# Why exhaust leaks screw up o2 sensor readings **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [October 25, 2006, 12:39pm UTC](https://forums.speedlife.net/t/why-exhaust-leaks-screw-up-o2-sensor-readings/19287 "2006-10-25T12:39:43Z")\ **Posts on this page:** 1\ **Showing post:** 3
**Author:** ![newman](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/newman/32/7569_2.png) [@newman](https://forums.speedlife.net/u/newman)\ **Post date:** [October 26, 2006, 5:43am UTC](https://forums.speedlife.net/t/why-exhaust-leaks-screw-up-o2-sensor-readings/19287/3 "2006-10-26T05:43:03Z")
that’s not the only reason that ambient air comes in. It’s mainly due to an “entrained gas” effect. Similar to how orienting the ends of two straws at a 90 degree angle, then submerging the free end of one into liquid, while continuously blowing into the remaining end will create a negative pressure zone large enough to raise the water up the straw and then spray all over. This is a continuous stream of air. Not a pulse with a trailing low pressure zone. This is the principle that an eductor pump operates on: ![http://www.eductor.net/2m6-2.jpg](http://www.eductor.net/2m6-2.jpg) --- _[View the full topic](https://forums.speedlife.net/t/why-exhaust-leaks-screw-up-o2-sensor-readings/19287)._