1997 Explorer Bogs Down, Wont Go Over 20MPH

[josephc04]

I have a 1997 Ford Explorer with a 4.0 SOHC engine. It bogs down and won't go over 20 MPH. I'm showing codes P1405 and P1151. Would either of these codes cause that issue? I'm not even sure how to start diagnosing this.

[shorod]

A diagnostic code will NEVER cause an issue. A diagnostic code is just that, a diagnostic aid to help a technician decide where to start looking. An issue can cause a diagnostic code, but not the other way around.

The P1151 is defined in the factory service manual as have the following possible causes:
H40 DTCs P1131, P1151, P1132 AND P1152: UPSTREAM HO2S(S) NOT SWITCHING. DTCs P1130 AND P1150: FUEL SYSTEM NOT SWITCHING AT FUEL TRIM (RICH OR LEAN)

• Diagnostic Trouble Codes (DTCs) P1131 bank 1 (Cylinder 1) and P1151 bank 2 indicate the fuel/air ratio is correcting rich for an overly lean condition. The HO2S voltage is less than 0.45 volt. DTCs P1132 bank 1 (Cylinder 1) and P1152 bank 2 indicate the fuel/air ratio is correcting lean for an overly rich condition. The HO2S voltage is greater than 0.45 volt.
  DTCs P1130 and P1150 indicate the fuel control system has reached maximum compensation for a lean or rich condition and the HO2S is not switching.
  DTC/HO2S Reference List
  • HO2S-11 = DTCs P1131, P1132 and P1130
  • HO2S-21 = DTCs P1151, P1152 and P1150
  Possible causes:
  Fuel system
  
  • Excessive fuel pressure.
  • Leaking fuel injector(s).
  • Leaking fuel pressure regulator.
  • Low fuel pressure or running out of fuel.
  • Contaminated fuel injector(s)
  Induction system
  
  • Air leaks after the MAF.
  • Vacuum leaks (vacuum lines and gaskets).
  • Restricted air inlet.
  • PCV system.
  • Fuel purge system.
  • Improperly seated engine oil dipstick.
  EGR System
  
  • Leaking gasket.
  • Stuck open EGR valve.
  • Leaking diaphragm.
  Base engine
  
  • Oil overfill.
  • Cam timing.
  • Cylinder compression.
  • Exhaust leaks before or near the HO2Ss.
• Check intake air system for leaks, obstructions and damage.
• Check air cleaner element, air cleaner housing for blockage.
• Verify integrity of the PCV system.
• Check for vacuum leaks.

For the P1405, the service manual suggests the following:HE50 DTC P1405: INSPECT UPSTREAM PRESSURE HOSE CONNECTIONS

• Diagnostic Trouble Code (DTC) P1405 indicates that Continuous Memory Self-Test has detected the exhaust manifold side (upstream) differential pressure feedback D.P.F. EGR sensor pressure hose is off or plugged.
  Possible causes:
  
  • Improper upstream pressure hose connection.
  • Upstream pressure hose plugged.
  • Plugged or damaged pressure pickup tubes.
• Key off.
• Inspect upstream hose at D.P.F. EGR sensor and orifice tube assembly for disconnect or poor connection.

One common possible cause for both codes is a vacuum leak, specifically associated with the DPFE. I'd suggest you start your search at the DPFE, checking to make sure the hoses are still in good shape and that neither of the passages are plugged. If work was performed recently that may have involved removing or disconnecting the DPFE, check to make sure the hoses did not get reversed or damaged.



-Rod