Cel p0135, p0401, p1131

[westonmt]

New here! Great site! Just bought a 2001 Ranger 4x4 4.0L for cheap in pretty good condition with a few kinks to iron out. More specificially a CEL that produces P0135, P0401, and P1131. Replaced the upstream O2 sensor and no exhaust leaks in the EGR system that I could find. O2 sensor had no effect on the P0135 code. Funny thing is that the motor idles and runs at speed very well...just a slight hint of roughness at idle. Would you guys recommend throwing a DPFE at it? I'd hate to throw parts at it if someone else has had this experience or a better recommendation than spending blindly throwing money away... I searched the forum and couldn't find this combination of codes and everyone else had rough running engines. I appreciate any help!

 

[westonmt]

Additional info... Previous owner says that the dealership changed the O2 sensors. Light went off for a week then came back on. Dealership says they can't determine the cause after it came back on and that "sometimes Rangers do this". I replace the DPFE with no luck and double checked for vacuum leaks. Maybe this additional info can help someone help me... Should I be breaking out the meter to look for a short to ground? Thanks in advance.

 

[westonmt]

fixed

Sorry to revive this old thread but wanted to put in the corrective action in case someone does a query. It took me a while to finally get the time to tear out the passenger side wheel well and crack open the EGR and get to the bottom of these problems. Solutions below:

P0401- My EGR tube was blocked by carbon; cleaned it out and seafoamed the intake

P1131 and P0135- Checked for 12v on the passenger side O2 sensor plug. It was dead... no continuity on any of the other wires to the PCM... pulled the plug off the connector (tuck on the back side of the engine block and hard to see... connector wires were completely severed... previous owner lived in the middle of no-where and we were deployed to Afghanistan for a year= mouse probably ate through it... ran 3 new wires to the PCM and a wire to the fuse box under the hood to the appropriate fuse (fuse 18) for the 12v supply. Problem solved!