1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Major ICE Idling Problem, Shakes, Dies

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by jb154, Apr 6, 2014.

  1. jb154

    jb154 New Member

    Joined:
    Apr 6, 2014
    5
    0
    0
    Vehicle:
    2005 Prius
    Model:
    N/A
    Last week after a big rain I was driving home and while stopped my 2005 Prius ICE started misfiring really bad and couldn't shut off when at a stop sign. Yellow check engine light came on. Two days before this I had the oil changed and changed the air filter.

    Next day my wife drove the car and the ICE died on her after shaking badly. The red exclamation point came on with "problem" and the red car that means take to dealer now. I was able to start car, brought to dealer, they couldn't reproduce the problem, so cleared the codes (still charged me, ugh).

    Two days later driving on the interstate I feel misfire, yellow check engine light comes on. Kept driving it throughout the week. Noticed the ICE had a little difficulty shutting off while stopped. Brought to Autozone they said it was a code for air / fuel ratio problem (P0171). I double, triple checked that air filter is in there secured.

    Drove all day yesterday out of town, no problems, about 200 miles round trip. Was raining most of the day. Get home and then at the stop light it starts shaking uncontrollably again. ICE can't shut off. Get home, restart the car, shakes uncontrollably after ICE cuts on, red lights come on again and ICE dies (have to turn off the car and turn back on). When ICE dies the yellow brake light comes on.

    To summarize - the ICE has intermittent difficulty idling and shutting off when stopped in traffic. It shakes uncontrollably when it is at its worst and then dies (has to be restarted).. Had P0171 code. Battery has no issues charging, etc.
     
  2. fotomoto

    fotomoto Senior Member

    Joined:
    Apr 22, 2009
    5,600
    3,776
    0
    Location:
    So. Texas
    Vehicle:
    Other Hybrid
    Check for anything left unplugged (wiring or hoses). MAF sensors usually have their own codes but check if its dirty or unplugged. These suggestions should have thrown codes immediately but maybe something worked loose during the 200 mile trip and the rain may just be a red herring.

    GOOD LUCK! (y)
     
  3. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    108,213
    49,192
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    faulty o2 sensor? how many miles on her?
     
  4. jb154

    jb154 New Member

    Joined:
    Apr 6, 2014
    5
    0
    0
    Vehicle:
    2005 Prius
    Model:
    N/A
    128,000 miles

    XT557 ? 2
     
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,200
    6,464
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    DTC P0171 means that the air/fuel ratio is too lean. Clean the mass air flow sensor, located on the engine cleaner housing. Use only the correct MAF sensor spray. Check the wiring harness connector to the MAF sensor to make sure there is no corrosion on the contacts.

    Since the problem happens when it is raining, part of the problem could be that moisture is getting into a connection.

    Make sure that the clamp which secures the engine cleaner housing to the throttle body is secure. You don't want any unmetered air getting in, past the MAF sensor. Make sure there are no cracks in the plastic engine cleaner housing.

    Also make sure that the engine oil cap is tight and the oil dipstick is fully inserted. Check the PCV hoses to make sure they are secure. All of those are potential places for unmetered air to enter the engine and make the air/fuel ratio leaner than it should be.
     
    cwerdna likes this.
  6. jb154

    jb154 New Member

    Joined:
    Apr 6, 2014
    5
    0
    0
    Vehicle:
    2005 Prius
    Model:
    N/A
    I cleaned the MAF sensor and found a piece of trash in it! Its either from when I changed the air filter or at the oil change place when they showed me the dirty air filter.

    The red exclamation point and problem error are gone! However the check engine light is still on. Will I have to drive it around some first for it to turn off, assuming there are no other problems?

    Thanks for all of advice on this thread. Saved me from wasting more money and time.

    XT557 ? 2
     
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,200
    6,464
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Disconnect the 12V battery negative cable where it bolts to the body for a couple of minutes, to clear the engine ECU DTC. Then reconnect the cable and make the Prius READY to see if any warning lights remain on.

    If so, then have the DTC read again.
     
  8. jb154

    jb154 New Member

    Joined:
    Apr 6, 2014
    5
    0
    0
    Vehicle:
    2005 Prius
    Model:
    N/A
    Just a follow up. Its been about a week and CEL has not popped up again! Car is running great. This little experience has motivated to do some other preventative work on the car myself. Thanks!

    XT557 ? 2