i get code P0171 on the computer due to having a shaky take off, smell of gas, and check engine light on. I cleaned out the map sensor thats on the intake. it kind of solved the problem a bit but it still shakes upon take off. The truck is a 1996 gmc sierra 2500 vortec eng and 170000 miles. Any ideas? Thank you
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1996 GMC 2500 Pickup Question: map sensor
Answer #1mastertech6371 April 03, 2010, 21:14Master
171 is usally a indicator of a vaccuum leak causing the long term trims up. fuel pressure, pcv, mass air flow sensor and intake leaks are common problems. by the way, cleaning the mass air flow works in less than 1% of the time.
the breaking up n accelaration is probably plugs and wires.
take it to a pro and let him tell you what it needs instead of throwing parts at it trying to fix it.