Hey, I'm new to this forum. However I've been on the EvoM forums for 5+ years after owning and building a 700hp evo. I ended up getting rid of my legacy outback 2 weeks ago, and purchased a 2001 montero limited two days ago. It had 0 codes when I got it. I filled it with unleaded and took it through DEQ, where it passed. After driving it for another 45 minutes it threw a check engine light. Luckily I was only a few minutes from home. When I got home I got these two codes.

P0170
Fuel Trim Bank 1

P0125
Insufficient coolant temperature for closed loop control

Has anyone had these codes before? I was wondering if it could've been thrown from getting gas? I'm not a mechanic however I know my way around wrenching on a car. Wondering if it's a faulty o2 sensor? From reading these codes could be anything but I'm curious if when they throw the code together it's easier to pinpoint the problem. Any and all help is greatly appreciated.

Thanks,
Sy

 

Its very likely that both codes are co-dependent (one malfunction triggered both). Please retrieve freeze frame data for both codes if you can an post it here.
#1 suspect is an intermittent fault with the engine coolant sensor. Having freeze frame data might help to confirm that. Just in case, check all vacuum lines to make sure nothing is disconnected and no hoses are cracked. Having a bad (cracked) vacuum hose will set P0170.