My 03 Montero Sport

Started throwing the following codes;
Current Fault Log
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P0171: System too Lean (Bank 1)
P0174: System too Lean (Bank 2)

Pending Fault Log
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P0401: Exhaust Gas Recirculation Flow Insufficient Detected

Any help would be appreciated.

 

Most likely you have a vacuum leak somewhere in the intake manifold. Check the rubber intake hose after the MAF (after air cleaner) and up to the throttle body. With the engine running at idle, flex the hose, move the ends near clamps, and see if you can spot any areas where you will hear loud hissing - air entering system unmetered. It is also possible that one or more vacuum hoses that are on the intake manifold have disconnected or got a crack in them and allowing extra air to come in. Check/trace all the vacuum hoses to make sure they did not disconnect/break.

EGR error most likely is a secondary to System Lean.

 

In my case I mark error just after they tuned it with buoy