Question, i have a 2010 mazda 3 2.0 and i have changed both O2 sensors, maf, egr valve, and i am still getting P0171 code for system too lean, any body have had this issue and know how to fix it? i do have a cold air intake and exhaust on the car.
It's probably not the cold air intake but those things are pointless on modern cars and screw with the MAF. If you have the original intake, I would put it on to rule it out.
The engine computer is saying you are getting too much air or too little fuel in the system.
Check all vacuum lines for cracks\leaks. Do the old propane\brake cleaner\carb cleaner trick to find if you have one.
Do a fuel pressure test. Or if it's easy on these cars, consider replacing the fuel pump.
