Check engine soon popped up bout 4 days ago, autozone scanned the code and it said it was a bad maf sensor and it also said ecm needs reprograming. But car runs great, no stalling and flies like a bat on crack when i stomp it, but the car gets HORRIBLE gas milege! I can also hear like vaccum sucking coming from rear of engine but that may be normal, what should i do?

 

If you don't have the code(s), then what someone said is pretty irrelevant as they might as well be walmart employees.

Bad fuel economy definitely sounds like maf, but it literally sounds like you have a vac leak, too.

 

Cool, i will check around the upper intake for the v leak, i hope the last guy put the intake plenum back on correctly, what would happen if the intake was inserted wrong?

 

Well it turns out not to be the maf sensor! the code I got was p171 fuel system too lean, bad o2 sensor, bad maf and exhaust leak are possibilities! I noticed one day my car got louder, I looked under the car, and the exaust pipe that connects to the muffler completely rusted and fell off! theres no pipe connected to the muffler! shop will charge me $60 to weld a new pipe in, so that's more than likely the cause of my check engine soon light.