I am currently having problems with my 05 Tribute stalling when stopping at a traffic light or a stop sign. It has done it twice with a month in between. I had to have it towed once and it finally ran the second time. It will run as long as you are in park or neutral. When I put it in gear it dies. No lights have come on so the mechanic cannot get a code. I took it to a muffler shop and they told me that it will need all new catalytic converters and oxygen sensors. After reading your posts I understand it can be the mass air flow sensor or the coils. I do not have tons of money to pay to fix it so I would like to get it right the first time. Any suggestions?

 

There should be pending codes I would imagine, ones that wont trip a light and you need more than a basic scan tool to read (Snap-On Modis as an example). The muffler shop sounds like they are trying to milk you for things you dont need, on a '05 there should be an O2 sensor after the cat that tells the ECU when its failing/failed, even if that sensor is bad there would be nasty smells from exhaust, cat converter not heating up, rattling from cat, louder exhaust, quieter exhaust etc.... My sister has a '99 Explorer and had the same issue with stalling when put into gear and failing to restart, her problem was a tired fuel pump, plugged fuel filter and a filthy, dirty intake system from the air-box all the way to the throttle-body, her throttle-body behind the throttle plate was caked in oil residue which was sticking the throttle, her IAC (Idle Air Control)valve was also gummed up preventing it from keeping a stable idle. She still has an occasional stall when putting into reverse but I suspect this is a transmission issue in the torque converter lockup clutch and not engine related.

So my suggestion is to give it a nice tune-up, plugs, wires (if it has them), fuel filter (if its never been changed since new in '05 your pump is getting close too), intake system (air-box {it has sensors too}, MAF, throttle-body, IAC), check your vacuum lines (with engine running CAREFULLY and SPARINGLY spray starter fluid around the rubber vacuum lines and wait till all spray is dry before spraying again, you will find a bad line when the engine RPM changes (usually higher) then drops back down. Oh a sticking EGR valve can cause issues like this as well.

 

Putting on all new Catalytic Converters and O2 sensors is very expensive and not necessary especially when your check engine light is not on with no engine codes. But what do you expect from a muffler shop! What kind of mileage do you have? Clean your MAF, throttle body. Have you done any maintenance like change spark plugs or PCV Valve? Being a 2005 vehicle these things should have been done by now as well as what Mazda Tirol said. Cars are complicated. Good preventative maintenance means your catalytic converters and O2 sensors will last longer (that's when it is expensive). Have you ever changed your transmission fluid! It is time!