# Got a P0171 CEL



## jblackburn (Apr 14, 2012)

Vacuum leak. 

Check the PCV hose into the front of the air box.


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## JcT21 (Apr 20, 2011)

i had this code yesterday. dealership told me i had a loose oil fill cap. dont sound right. maybe it was...


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## jblackburn (Apr 14, 2012)

JcT21 said:


> i had this code yesterday. dealership told me i had a loose oil fill cap. dont sound right. maybe it was...


Yes it does. A loose oil cap will cause a massive vacuum leak that the O2 sensor picks up on when the readings don't agree with the mass airflow sensor. 

My Saab would actually have such a big vacuum leak that it would stall every time when the oil cap was loose.


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## titan2782 (Nov 4, 2011)

Mine went away. Pretty sure it was a combination of the remaining octane booster i used with my low tank of gas and a very cold night while not letting it warm up before driving. Went away the next day and haven't seen it since.


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## KaP10 (Mar 18, 2015)

Could be a Bad Valve Cover


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## SneakerFix (Jul 28, 2013)

KaP10 said:


> Could be a Bad Valve Cover


Did you happens to check how old this post is?


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