What to look for on 2000 Ford Taurus to correct P0171 P0174 Cleaned Mass air flow replaced coil 3 repaired vacuum leaks on valve covers?

Answer 1

First off, you can't have a vacuum leak from a valve cover. Do you mean the upper intake plenum?

Cleaning a MAF rarely solves the problem, you likely have to replace it! A good indicator of a bad MAF is incorrect BARO pressure reading. If you have access to a scan tool that will give you live data, check that. Barometric pressure will vary depending on your altitude, where I live, readings vary between 98 to 101 kpa.

Another thing to look at is your calculated engine load while you're accelerating at WOT from about 50km/h up to about 80km/h at least. You want to see the engine load hit at least 90%. At the same time your MAF reading should be well over 100gps, probably around 120gps.

Hope this helps!

Code P0171 is System too Lean (Bank 1) That can be many things. Don't spend money throwing parts at the problem. My advice is to take it to a professional who has the knowledge and tools to find and repair the problem.

I had a similar problem like this. First I was told that I needed to replace the

"Mass Air Sensor" That didn't work for me, turned out I had a leak in one of my pipes that triggered the codes. My best advice is to find a trust worthy street mechanic or small shop around the neighborhood, to find the problem. It will be way cheaper. I dont know what area your from, but the shop that fixed mine was "Grand Prix" there located at 9909 Bustleton Blvd the Northeast Philadelphia area. You can Google the address to get the phone number!