Edmunds Answers



  • karjunkie 09/26/09 9:50 am PST

    P1128 refers to a "lean fuel trim condition". It is most frequently either a vacuum leak or a MAF sensor fault. Both can cause a lean condition over time. I would go right to checking for vacuum leaks first. Look at all the vacuum hoses coming off the intake manifold and check for cracked hoses or a loose connection. Then, using starter spray, spray all around the intake manifold base to see if the engine surges at idle. If so, you'll need to replace the intake manifold gasket. The MAF sensor can be cleaned with CRC MAF sensor spray available at most auto parts stores. Just remove the sensor from the air intake plenum and spray the MAF wire until it is shiny clean but do not rub it. Let it dry and then replace it. Let us know if you have any follow up questions!!


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