99 GP GT Stalls - Code P0452

[eippermx]

My '99 GP GT started to intermittently chug while driving 55 -65 mph. I drove immiediately home (30 miles) in time for my red GP to quit running when I parked the car.

I was able to start the car only for it to stall and die. I coded the car and the scan tool reported an EVAP code pending, no DTCs stored. I thought maybe what I was looking at was a fuel starvation problem.

I put a fuel pressure gauge on the fuel rail and it read 42 psi static, 42 - 50 psi when the engine was revv'd. I understood fuel pressure should be 48-55 psi. I replaced the fuel filter. Still had the same problem. I replaced the fuel pump with a used unit that had low miles on it. Pressure is up to 48 static, 48-55 psi when the engine is revv'd.

Replacing the pump did not solve the problem.

I fired up the car let it warm up for a couple of minutes, put it in drive, it stalled, and died. I noticed the SES light was lit, where as previously it was NOT. I coded the car and retrieved code P0452. The scan tool indicates the evap emission system pressure sensor/switch has a low input.

Can some one enlighten me as to what, where, and how to remove this sensor? Or is there something else that is the underlying problem that is ghosting as a P0452. Appreciate your help!

[BNaylor]

The P0452 DTC sounds ancillary to your original problem. It means there is a short circuit in the tank pressure switch circuits. The pressure switch is located on the top of the fuel pump pod so you should check the wiring and electrical connector to it. Another possibiity is the pressure switch in the pulled (used) part is bad. Your current fuel pressure readings look normal.

[eippermx]

Thanks Bob! Swapped the sensor with the one from the old fuel pump assy and solved the problem.