2017 Toyota Highlander with Lean Codes on both banks


Staff member
If you have a 2017 Toyota Highlander with Lean codes on both banks over 30% LTFT (also with possible EVAP code) then the problem is the EVAP Purge Valve getting intermittently stuck open. We are seeing quite a few of these.


I have a 2017 Highlander 3.5 80,000 miles, check engine light came on and only problem we’ve had is after filling up with gas which just turn over and wouldn’t start, had to let it sit for about 5 minutes before it would crank. Have codes....p0174( system too lean bank 2) p1170 fuel performance/port injector p0171 system too lean bank 1 p0505 idle air control system.....thanks


Same car 2017 Highlander 3.5 72k miles while driving in highway from nyc to boston had check engine and awd light. Pulled over start diagnose and got 3 errors:
P0505- idle control system
P0174- system too.lean bank2
P0171- system too lean bank1
Clean codes
Turned off the engine.
Try to turn on, it does just cranking but didnt start
Tried for several times and after the fifth time it did start. Engine rpm at 1200 in idle..

Stoped after 80 miles. Same issue.
3 times the same day.
Disconnect the battery for 15 minute.
Connect negative pole again.
Drove for 12 miles no issue at all no errors
Idle rmp 780..
Any idea?


This sounds like the issue I'm seeing. Got CEL on with codes P0171, P0174, P117b, P0441, P0455
Cleared codes
Came back after about 600 miles
Cleared codes again knowing I was about to fill up.
Filled up tank, wouldn't start.
Sat for about 5 minutes, started and ran fine, no codes yet.

If this is the EVAP purge valve, how does one go about fixing it?


3rd time in a month Check engine/AWD lights come on. Two weeks ago, I was putting gas in my Highlander, then it wouldn't start! Waited about 5ish minutes and is started right up! My mechanic said the codes were PO171,PO174,PO455,PO505. My mechanic replaced the Purge solenoid. WHY has Toyota NOT addressed this issue? They recalled the 2018 and 2019. Time for Toyota to step up and take care of their customers

Kevin Geiger

Mine just started doing this. Codes P0171, P0174, P0455 and P0441. Within the last couple of months I did change the spark plugs myself, and so I replaced the intake plenum gasket, had all kinds of hoses off, etc. I did take the throttle body off and forgot to buy a new seal so I did leave it there. Hopefully that's not where there is a problem. This has only happened after driving very long distances, filling up with gas and then trying to start it right away. Probably take to dealer to look at it.