P3190 - Time to Replace the Throttle Body, Should I go New or Used?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Kashmir, Oct 8, 2021.

  1. Kashmir

    Kashmir Junior Member

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    Back in August my '06 threw the P3190 code in conjunction with P0A0F. Consulting the sage advice on this forum I removed the throttle body and cleaned it and the MAF. Both codes cleared up and response improved!

    Now in October both codes are back and I suspect the cause is a defective MAF sensor. There's some conflicting information regarding if I can replace just the MAF sensor or if I have to replace the whole throttle body. Can I replace just the MAF sensor?

    If I cannot replace the MAF sensor; is getting a new or used throttle body the way to go? I've seen new ones from $300-$800. Prius chat has always given me good council and I look forward to reading the suggestions!
     
  2. JC91006

    JC91006 Senior Member

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    I think if the MAF sensor is bad, it will throw a specific code for the MAF sensor.

    When was the last time you did a complete tune up? Plugs/coils/replace injectors/air filter?
     
  3. ChapmanF

    ChapmanF Senior Member

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    I haven't really used the phrase "tune up" since around high school (while ago), when cars really did have bunches of things that wore or went out of adjustment frequently, and there was sort of a regular ritual of putting them all right.

    With newer cars, it seems that there just aren't flocks of things that regularly need that kind of attention, only every now and then something does, and you just do some diagnosis to figure out which thing that is, and fix that.

    If there's a MAF sensor problem, it is super easy to replace on its own. As for the throttle body, I've hardly ever heard of one needing replacement.

    P3190 is a pretty nonspecific code though. Means the engine's producing much less power than it should. Pretty long list of usual suspects to test. Most will usually be fine, and you'll find a culprit that isn't.
     
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  4. mr_guy_mann

    mr_guy_mann Senior Member

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    One of the first things I would do is to view engine data while (someone else is) driving the car. Specifically I want to see what fuel trim is doing. Fuel trim is the ECM adjusting the amount of fuel injected based on readings from the Air/Fuel sensor, and is the end result of every system- air filter, injectors, fuel supply, ECM and sensors, engine mechanical, etc. Short Term trim is a direct response to the A/F sensor, while Long Term trim tries to keep Short Term trim centered near 0%. Short plus Long Term trim = total fuel trim. Ideally everything stays as it was from the factory (near 0%). As parts wear the system doesn't work quite as well (or a fault occurs) and the ECM has to make adjustments, (+) trim if it's adding fuel, (-) trim to take some away.
    If fuel trim on your car is near 0 (+/-10%) under most all conditions, that can eliminate many possible problems that would not be causing your codes. If trim is off then you might be able to gain a diagnostic direction by recording what the values are under different engine operating conditions. Whatever is going on it's some fault that the ECM can't monitor directly- such as fuel pressure. (I would expect the ECM to code most throttle body faults- just like I might expect a MAF fault to set fuel trim - lean run codes)
     
  5. SFO

    SFO Senior Member

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    Do you need the workups, or have you already been through the workups for the above DTCs?