Ive had this problem over a year and i cant fix it. I had change my intake gaskets, coils,spark plugs , air filter , clean the MAF sensor, both 2 of bosch o2 sensors , changed my CAT converter because it had a p0420 so it got cleared and still the check engine light doesnt turn of for the p0171 which is running lean! The only thing I haven't changed is the Fuel injectors and the fuel filter. My Long Fuel trim is showing 40.1% when it should be below 10%. Please help!! Any suggestions would be great.