peterjiang4648

1 hour ago, RX400h said:

Here's an interesting read:

FINALLY SOLVED! P0171 and P0174 Codes!!!! - ClubLexus - Lexus Forum Discussion

Thank you so much, I will read it carefully.

2009 RX350

trouble code P0171&P0174

I used another vehicle's mass air flow sensor to replace my car's mass air flow sensor. And through the similar method I replace the B1S1&B2S1. but the long FT was still high. I have no idea about the problem.

I attach the "trouble code.jpg"、“700 rpm mass air flow.JPG”、“700 rpm short FT & long FT.JPG”、“1800 rpm mass air flow.JPG”、“1800 rpm short FT & long FT.JPG”.