# 97 Taurus P0303 code

**URL:** <https://community.cartalk.com/t/97-taurus-p0303-code/1786>\
**Category:** Maintenance/Repairs\
**Created:** [July 16, 2007, 1:42pm UTC](https://community.cartalk.com/t/97-taurus-p0303-code/1786 "2007-07-16T13:42:23Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Brian\_Central\_IA](https://avatars.discourse-cdn.com/v4/letter/b/b5a626/32.png) [@Brian\_Central\_IA](https://community.cartalk.com/u/Brian_Central_IA)\
**Post date:** [July 16, 2007, 1:42pm UTC](https://community.cartalk.com/t/97-taurus-p0303-code/1786/1 "2007-07-16T13:42:23Z")

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Good day to all…  
  
 I have a 97 Taurus 3.0 OHV that has aprox 25k on a new crate engine. Recently I have developed a P0303 code. Cyl #3 misfire. The MIL is on, engine idles rough and smoothes out aprox 1500 RPM. Code appears when warmed up at idle or hi-way speed. Engine Vac is 15-16. I travel aprox 60 miles a day and MPG appears to not be affected.  
  
  
  
 Here is what I have done to this point. Replace Cyl #3 injector w/new, swap plug and wire from another cylinder, changed Ign coil and still no resolution. The EGR and Pipe was replaced because It broke when trying to remove it.  
  
 A compression ck has not been completed at this point.  
  
  
  
 What am I missing here? You assistance is appreciated.  
  
 Brian

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**Author:** ![Loafer](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/loafer/32/28_2.png) [@Loafer](https://community.cartalk.com/u/Loafer)\
**Post date:** [July 16, 2007, 1:47pm UTC](https://community.cartalk.com/t/97-taurus-p0303-code/1786/2 "2007-07-16T13:47:28Z")

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Check the compression in that cylinder.

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**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\
**Post date:** [July 16, 2007, 4:16pm UTC](https://community.cartalk.com/t/97-taurus-p0303-code/1786/3 "2007-07-16T16:16:35Z")

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With the vacuum reading of 15-16 I would suggest a vacuum leak probably at the intake manifold near the #3 cylinder. Spray some carb cleaner around the intake and listen for an rpm change.

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<div class="post-metadata">

**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\
**Post date:** [July 20, 2007, 12:05pm UTC](https://community.cartalk.com/t/97-taurus-p0303-code/1786/4 "2007-07-20T12:05:47Z")

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I sprayed carb cleaner around the intake area again with no signs of a vacuum leak.  
After the Compression check on Cyl #3, I found only 60psi pressure compared to 160 psi in other cylinders. Since the engine is covered under warrenty, I will let the shop who installed it take it from here. Thanks for the follow up. Brian