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I can't figure what my problem is. To date I have exchanged all the gas in assumption that I put in the wrong blend of ethanol. Changed the Fuel Filter, cleaned the MAF Sensor and just recently changed the first O2 sensor. After changing the O2 sensor it took much longer, about 40 miles for the check engine light to come back on.

When I hooked it up to my buddies laptop, it showed that the system was lean above 3000 rpm and the first O2 sensor was constantly changing voltage.

Any ideas what to look at next, the car runs ok, but I don't want to damage anything if i am running to lean. I would also like to get rid of the car and want to diagnose any problem. Doesn't look to good to prospective buyers if a check engine light is showing.
 

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Registered
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228 Posts
I can't figure what my problem is. To date I have exchanged all the gas in assumption that I put in the wrong blend of ethanol. Changed the Fuel Filter, cleaned the MAF Sensor and just recently changed the first O2 sensor. After changing the O2 sensor it took much longer, about 40 miles for the check engine light to come back on.

When I hooked it up to my buddies laptop, it showed that the system was lean above 3000 rpm and the first O2 sensor was constantly changing voltage.

Any ideas what to look at next, the car runs ok, but I don't want to damage anything if i am running to lean. I would also like to get rid of the car and want to diagnose any problem. Doesn't look to good to prospective buyers if a check engine light is showing.

if all you had was a p0171 code and nothing else it is not the O2 sensor.....read this http://www.obd-codes.com/p0171
 
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