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2007 Lexus ES350 long terms running lean, no codes (at the moment). Lost (LONG)
I bought a new OEM MAF sensor and to no avail, it's still underreporting. I reset the ECU by removing the ETC and ECI Main fuse in the fuse box for a few mins before I did the test, rather than removing the negative battery cable. I didn't drive, I just let the car warm up to idle.
So what is tested so far
Both upstream A/F Voltages around: 3.3V
Barometer: 100-101kpa @altitude 4m/13ft
New OEM downstream O2 sensors
Fuel pressure 1-2psi above spec, negligible
DIY Smoke machine shows no leaks when putting smoke into intake.
An update. So I have confirmed a slight leak at the brake booster, fine.
For the MAF, documentation calls for testing in park/neutral as I wrote above and the specifications fail. I got a friend with me yesterday finally so he can observe as I drive. When I shift to DRIVE, the maf sensor readings are in specification. Why does the test call for neutral/park, shouldn't I care for when it's in drive?
Hi, I am new here . And also search for answer for my 2011 camry LE is running lean like yours . High LTFT 18% when rpm is high .
I have read all your posts, and other posts, and also from other websites. I may suggest you take a look at fuel injectors (clog) . Maybe there is a leak at the seal of injector(s) . I will check for my car too .
If your camry is the v4, it is not the same engine. The v6 is a pain to get to the 3 rear cylinders and anything related to it, so I don't have easy access to check for leaks. The front three seem to be fine
An update I guess. I have determined the lone cause is the brake booster. It is not leaking bad enough where it requires immediate repair or replacement, but it's a slight leak. I reset the computer so it can relearn, and so far the total trims stay within nominal range. I've driven the car on around 400-500 miles in the past few weeks on some road trips, and fuel trims long term haven't passed 10-11%.
hi,
You should watch this video . Please search for 427k mile toyota, lean p0171 fixed by ivan . I think partially clog injector will make imbalance which caused lean code .
For my car, I think I will change all 4 injectors (remanufactory) since it is 200K miles .
Thank you for the resource. Unfortunately I no longer have the time to diagnose the car. Would have to be something I look at in the upcoming months, but feel free to post updates about your vehicle.
In the service history the dealer recommended the car had an induction service for the fuel injectors, so maybe they noticed they were clogged. I've thought about doing it for mine.
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