1995 Ford Windstar LX 3.5L Error Codes?

Both codes mean a lean condition on the engine (P0171 for Bank 1 and P0174 for Bank 2). This is almost always because of a vacuum leak. Check all vacuum lines and vacuum operated equipment (EGR, brake booster, fuel pressure regulator, etc) for leaks. It could also be the intake manifold gasket. Use a spray bottle with soapy water to try to isolate the leak if you cannot hear the leak.

Lean bank 1 and bank 2 , and throttle actuator system fault. Check reason for lean codes 1st, vacuum leak(s), air inlet boot and hoses, or low fuel pressure / clogged filter. Repair as needed then clear codes and recheck .

the codes you have transnisson codes
po743 torque converter clutch wring problem or connectors
po746shift solenoid/wiring
po760 the same
po174 mixture to weak bank 2
po171 to lean bank 1
po401 egr valve
sounds to me that you have corroded connector/or wiring problem to the power control/transmission module good luck

#1 is the egr position sensor #4 Is for single cylinder misfire so this could be the coil or a bad plug or wire ..but with fords should check for a vacume leak that can cause a misfire to .....#2#3 are 02 sensors before i would change them i would check the mass air flow sensor ..Hope this helps

those codes are for lean engine condition look for vac leaks at the back of engine to the pcv valve could hear hissing noise with engine running also check egr valve to be stuck open also when was last fuel filter changed? hope this helps .

if the light is flashing it most like hasly some sort of misfire or converter failure, p0171 and p0174 is lean bank 1 and 2, replace you upper and lower plenum gaskets, while they have they off have they replace your ignition coil, plugs and wires, windstars are known for 2 things, lean codes,(plenum gaskets) misfire(bad ignition coil)

Try cleaning the MAF. Here is more info on the codes:
http://www.aa1car.com/library/ford_lean_codes.htm

Symptoms of a faulty Camshaft Position Sensor can include hard starting (or no starting), rough running/misfiring and/or loss of power.

Code 340 COULD be caused solely by a faulty Camshaft Position Sensor. However, this code refers to the entire circuit. So, replacing the sensor may not fix the issue. The problem could lie in any part of the circuit - the sensor itself, the wiring, or the PCM.

Codes 171 and 174 typically appear together. They are caused by the 02 sensors reading too much air (lean) in the exhaust. In most cases, simply cleaning the MAF sensor does the trick. I typically take it off and spray it with electronics or brake cleaner. Just make sure it dries before reinstalling. If this doesn't eliminate the codes, inspect all vacuum and PCV hoses, check for a dirty fuel filter and ensure the furl pressure is within limits.

For clarification, the first trip to the shop your car showed codes 402, 732, 733, 171 and 174. After changing the DPFE/EGR, did ALL those codes go away and now only codes 340, 171 and 174 exist? Or do you have the second set of codes in addition to the first codes?

Hello;
With those codes, the first place I would check is the fuel pressure. Also check the fuel filter and replace it if you haven't already. Then clear codes and recheck. Even if your fuel pressure is with in range it still may not push enough fuel to operate your vehicle.

That's an 02/oxygen sensor code means that bank 1 or 2 is too lean. Good Luck contact if you need more help.