Hey everyone,

I’m trying to get some help on an issue I’ve been chasing on my daily driver, a 2014 Lexus IS250.

Recently the car started throwing P0171 and P0174 (Bank 1 and Bank 2 too lean). Around the same time, I also started getting an intermittent no-start issue (seems to happen after fill ups but not always) where the engine will crank normally but just refuse to fire. It doesn’t happen every time.

Since then I’ve also replaced/checked the following:

• MAF sensor

• EVAP purge valve

• Fuel delivery / fuel system checks (no obvious issues found)

• Smoke test and vacuum checks (no leaks found)

Everything I’ve been able to test so far looks normal, but the issue is still present:

• Both banks lean codes persist

• No drivability issues once the car actually starts and runs

• Intermittent crank-no-start still happens

At this point I’m trying to avoid just throwing more parts at it blindly. Has anyone run into a similar combination of symptoms on the IS250 or have any ideas on what else I should be looking at?