Hello Everyone,

I have a 2001 Montero Sport that has several codes. I need some help on narrowing down what needs to be replaced. The codes are:

P0174 - Bank 2 system too lean
P0154 - Oxygen circuit no activity detected (Bank 1 sensor)
P0421 - Warm up catalyst efficiency bank 1 below threshold
P0401 - Exhaust gas recirculation flow insufficient detected
P1400 - No DTC - None Found

Any help is appreciated.
Thank you!

 

Have you reset it and verified which codes returned?

 

I had it checked at a parts store. He thot it might be a converter but wasnt sure. He reset it, on the drive home the light came back on. Checked them again. Same codes.

 

I have a similar problem. I have P0401 and code P0421 pop off and I have swapped out both the egr valve and the egr solenoid. I reset the computer and drove around for 4 days before the check engine can back on. If anyone has any suggestions or solutions please message back.