Lexus RX300 P0171 and P0174 error code
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    Default Lexus RX300 P0171 and P0174 error code

    Hi everyone I have a Lexus RX300 3.0 2000 eidition. Some time when i start the car when the engine is cold the engine make some fluctuations but not all time, after the engine warmed it work perfect in idling without problem during idling. Now my big problem is when i put the acceleration pedal full the engine go only in 5000 RPM and no more. Now with full throtle open and engine 5000 RPM the engine light go ON. All the time the error code are P0171 and P0174. I have check everything, i have change ignition coil, injector, PCV valve, VSV valve and they are OK but no succes. I have try some other MAS AIR FLOW (not exactly with same number) but no succes. I have check all vaccum hose for leak but nothing. When I'm driving the car not have full power and it is not good during acceleration. When I'm driving and if i put the acceleration pedal full quickly the engine stall and the CHECK ENGINE LIGHT come ON. All the time with engine stacionary and driving the maximun of RPM are 5000 RPM no more. Please have any idea how can i solve this problem.

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    How many miles on the car?
    Do a smoke test and how old are your oxygen sensors?

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    the car have 169,000 KM. I have change the 2 oxygen sensor with 2 other from second hand but same think. I have try to disconnect 2 oxygen sensor and the engine work in same way. Only 5000 RPM or some time 5500 RPM not more even i disconnect oxygen sensor. And with this sensors connected is the same thing. I haven't do smoke test because i haven't smoke tester and with this model is difficult to do i think. I have try to block the throtle when the engine is runing and when i block the throtle the engine stoped (turned OFF). Today i have try with another MAS AIR FLOW but nothing. Im bored with this car

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    We all get them sort of jobs, some more than others

    ok, let's start a fresh, clear all fault codes

    then from cold go for a gentle drive until engine light comes on

    then leave engine running use eobd scanner read codes then hit "ff" or freeze frame
    write down, stop engine return to base see if same distances repeat.


    Then repeat, this time, gas pedal to the floor ignore it's limit when mil comes on
    read ff again then post here with description use different scanners if you can

    Was Banned For Being Certifiably Insane and Stupid

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    Mate thanks for your response. I have try that things. I have test with some diagnostic scnner like : Launch, Delphi, Autel, and TOYOTA diagnostic and it is same error P0171 and p0174. When i clear this error the engine light go OFF but no more 5000 RPM. If I try to put the pedal to the floor when the car is stacionary the engine light stay OFF (infrequently it go ON) but no more RPM. If i try to drive and put the pedal to the floor the engine light go ON and the car is in limp mode, anyway it run good during 5000 RPM and when I hold the foot to the pedal full the engine make BLLA BLLA BLLA (now the RPM are 5000-5200 RPM, full pedal). From idling to 5000 RPM everything is OK, when the RPM go 5000 engine make noise BLLA BLLA BLLA and no more RPM

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    OK get it to rev at 5000 rpm, turn ignition off then on whilst still running
    was a car in history, when cam sensor died and was temporay solution.

    as your tearing your hair out, rumor states some Toyota/Lexus just don't drive right
    no codes, unbolt egr and blank off, totally differant car

    if you haven't done egr do it next

    Was Banned For Being Certifiably Insane and Stupid

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