# Exhaust question

**URL:** <https://forums.speedlife.net/t/exhaust-question/245792>\
**Category:** Shift518 Automotive\
**Created:** [July 30, 2009, 3:41pm UTC](https://forums.speedlife.net/t/exhaust-question/245792 "2009-07-30T15:41:06Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![NedZ32](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/nedz32/32/6393_2.png) [@NedZ32](https://forums.speedlife.net/u/NedZ32)\
**Post date:** [July 30, 2009, 3:41pm UTC](https://forums.speedlife.net/t/exhaust-question/245792/1 "2009-07-30T15:41:06Z")

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The Z is down for a few days for a new water pump. In the meanwhile, I’m replacing the cats with test pipes since they’re clogged and produce a horrible smell once the car is warm. My question is, will running the engine open header cause any damage to the engine? I’ve read that you can damage the valves when you turn off the engine because of cold air being sucked back in. Any truth in this?

Btw, I’m not running this on the street. Just kind of a “shits and giggles” bs kind of thing.

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**Author:** ![88slowmarro](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/88slowmarro/32/6339_2.png) [@88slowmarro](https://forums.speedlife.net/u/88slowmarro)\
**Post date:** [July 30, 2009, 5:55pm UTC](https://forums.speedlife.net/t/exhaust-question/245792/2 "2009-07-30T17:55:39Z")

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ya can burn exh valves by doin it …but only if its really pounded on drive it semi ok and your fine

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**Author:** ![NedZ32](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/nedz32/32/6393_2.png) [@NedZ32](https://forums.speedlife.net/u/NedZ32)\
**Post date:** [July 30, 2009, 6:10pm UTC](https://forums.speedlife.net/t/exhaust-question/245792/3 "2009-07-30T18:10:25Z")

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Just want to fire it up for a minute in the driveway to hear it really lol

Thanks for the reply