P0171 Buick -

Question

97 buick lesabre limited 100,000 miles changed plugs wires fuel filter has rough idle sometimes and now check engine light is putting off a code system too lean is it the gas like the advanced guy suggested or something like the icm

Answer 1

P0171 Fuel trim lean Bank 1

Lean fuel trim for this engine is a vacuum leak that gets past the MAF (mass air flow) what a lean condition is is more air to fuel ratio. If this was the ICM you would have a misfire code that would be set, if this was fuel related such as low fuel pressure you would set a P0300. If there is only a P0171 you have a false air getting past the MAF.