Auto diagnosis

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Came across this story today: Debugging a CEL and thought I'd share it. Interesting how the secondary AIR injection system can fool the ECU into thinking there is a lean condition. More interesting is how long it takes to find and fix one "minor" issue.
 
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Happy B'Day neighbor! Funny, It's my B'day Thurs smile The wife might take me to Goody Cole's Smokehouse on RT125 near Epping 101E exit smile
 
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That story was a good read especially because I am suffering a recurring P0171 code in a 1999 Saab 4 cyl. I mentioned the code to a fellow who works on Saabs and a bad MAF sensor-which was mentioned in the article-was his first thought. A reader which gives you the operational parameters before and after a code is stored (the one used by the author) would be nice to have. Kira
 

supton

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Originally Posted By: ARCOgraphite
Happy B'Day neighbor! Funny, It's my B'day Thurs smile The wife might take me to Goody Cole's Smokehouse on RT125 near Epping 101E exit smile
Happy (early) birthday to you! We went out over the weekend, down to Concord, mostly to get out of the house on an otherwise boring day; tonight though is homemade lasgna. Yum. I just have to remember to hit up town hall and vote on the way home.
 
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Hawaii
Good article and fascinating website. On the Secondary Air Injection System tricking the ECU into a lean condition, this might be a favorable issue for those who want to "chip" their engines. Not saying it's good, but with the ECU giving move fuel to the injectors, this is what a "performance" chip does.
 
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If I am not mistaken, Mark Hicks is from Airtex (Wells Engineering??) Eric The Car guy visited their factory. Mark is extremely sharp guy and has published some of the best material on the automotive diagnostics. I remember printing every article he had written in the Motor magazine once I came across the website.
 
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