Hello...newbie here. I just bought a 2003 4Runner v6 2wd with 115k. It has no power..struggle to get over 20 mph. Felt like no gas and tranny won't shift at the same times. Check engine lite, VSC and ABS are on. Code P0171, P0174, P0420, P0430.

Cleared codes after sitting several hours and it runs fine up to 60 mph. 30 miles later, check engine lite, VSC and ABS lites back on. It can still be driven over 45 mph but with gently pressing the gas, if the gas pedal was press hard as in fast acceleration, it bogged down at 45 mph and no faster. Gently let go of the gas pedal and gently press it, it can go at highway speed at 70 mph even with all lites on.

This is what I have done after reading a lot of posts. Cleaned and replaced Mass Airflow sensor, put seafoam in gas tank. Runs fine for a few days, all lites come back on around 40 miles. Code P0171 and 174 are now GONE. Just P0420 and 430 are on. Drove ok for 1 week, and bamm, it bogged down to 20 mph...won't go faster than that. Engine lite, VSC and ABS lites are back on and all 4 codes are back. Reset engine lites, nothing.

Took car to Toyota dealer and was originally told need cat. converter. More testing, they now said 90% sure not cat. There is a TSB that shows those code...bad hose inside gas tank. Cost $380 to fix it. I am still thinking about it. Anyone has similar problems and solutions??

Sorry to bring back an old thread but were you able to get this resolved? I have an '06 with a V6 and I am receiving the same p0171 and p0174 codes. However, my truck eventually stalls at idle. I have cleaned the MAF and still the same thing. I am wondering if it is a fuel pump/filter issue or something related. I know both codes basically mean the engine is running way too lean. Any suggestions would be appreciated :-).