2002 Ford Taurus - Alleged EGR Valve and Sensor failure

2002 Ford Taurus
3.0L V-6
180K miles
Automatic transmission
Front wheel drive
Nothing aftermarket, as far as I know - I bought it used.

Okay, the story so far: I drove one block from work to the grocery store during my lunch break. When I came out of the store my Taurus wouldn't start. I had it towed to the shop, and they said they started it up and drove it into the bay with no problem. So they did some testing and told me that the EGR Valve and the EGR Pressure Sensor were malfunctioning, and it was going to cost more than $300 to fix it, but the car was currently running. I didn't have the money at the time, so I just paid them for the diagnosis and drove the car home.

A few weeks later the car stalled on the highway while my g/f was driving it, and it hasn't started since. Trying to save a few dimes, I replaced the EGR valve and the sensor myself since the parts were affordable. The car still won't start. I've read something online about the EGR Vaccuum solenoid, but the shop didn't say anything about that.

My question is, am I barking up the wrong tree, or should I try to replace the EGR Vacuum Solenoid? Could these be symptoms of something totally different? From the stuff I've read online, I've gleaned that anything from spark plugs to catalytic converter can cause the same symptoms. So I'm stumped...and my budget's pretty tight, so I'd like to do as much myself as possible.

Any insight?

Sounds like a fuel issue. You can have someone start the car while you spray carburetor cleaner into the throttle body. If it will run as long as you are spraying and die when you stop spraying, It is a fuel problem. The next step would be to check the fuel pressure. If it is a flex-fuel vehicle, it should have 30-65 PSI with the key on, engine off (when the pump is running.) If it is not a flex-fuel vehicle, it should have 39-65 PSI, key on engine off.

If the fuel pump runs, but pressure is below these specs, you will need a fuel pump. If the fuel pump does not run, you will need to check for voltage at the inertia switch. If the car is not a station wagon, the switch is located in the trunk, right side behind the trim panel. It will have a button on top of the switch. If it is a wagon, the switch is behind the back seat, right side behind the trim panel. You should have battery voltage to both wires of the switch when the starter is turning the engine over, or for about 1.5 seconds when you first turn on the ignition. If you get voltage there, then check for the same voltage at the fuel pump connector. If voltage is good, but low (or no)fuel pressure, replace the fuel pump.

One more thing, aftermarket fuel pumps have a high rate of failure, I recommend a genuine Motorcraft pump if one is needed....