Hey Scotty, I have a 2006 Lexus is350 RWD with 132,000 miles. My scan tool shows that bank 1 LTFT is -6% and bank 2 LTFT is +10%. You’ve said before that could mean a vacuum leak but I don’t hear anything sucking in the engine bay. Any ideas? Thanks and love the videos!
I don’t hear anything sucking
this is not a reliable test for vacuum leak
https://www.youtube.com/c/ScottyKilmermechanic/search?query=vacuum%20leak
You can usually identify a vacuum leak on your scan tool if the lean mixture becomes noticeably less when driving, particularly at highway speed. The amount of unmetered air getting in, relative to metered air is much less significant at speed. If it trends to 0, there's most likely a vacuum leak.
-6% on your LTFT B1 is probably dirty fuel injectors on that side. Run a few rounds of fuel injector cleaner or Shell V-Power through it and monitor it. Start with the simple stuff and work your way up.
Bank 1 is rich. Bank 2 is lean. Lean condition is caused by ECU, ECM, or other modules, vacuum leak, clogged fuel filter, weak fuel pump, faulty injectors, damage or broken gaskets, a dozen different sensors and timing is off and is advanced. There is a few more things it maybe as well. Rich condition is caused by ECU, ECM and or other modules, o2 sensor, map, maf, iat, coolant temp sensor, fuel pressure regulator, leaking injectors and rare cases timing. There is a lot it can be, you just have to norrow it down. Watch a few videos on how to read live data and to diagnose. It will make life easier.
Dirty fuel system can also cause lean condition. I forgot that one.