2011 engine light shake when starting after new plugs

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by icyrius, Feb 21, 2026 at 1:37 PM.

  1. icyrius

    icyrius Active Member

    Joined:
    Apr 10, 2016
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    Location:
    Florida, USA
    Vehicle:
    2014 Prius v wagon
    Model:
    Three
    Hello,

    I noticed after installing a new set of spark plugs (Iridium DENSO SC20HR11), the engine does a light 2 second shake when turning on after switching from ECO. However, the rattle sounds like it’s coming from the exhaust touching the catalytic converter protector I installed due to theft in my area. Could this rattle be caused by the new spark plugs? I should I try better gas in my tank or something?

    Thanks
     
    #1 icyrius, Feb 21, 2026 at 1:37 PM
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    114,496
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    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    How many miles on her? Are you losing any coolant?
    Where did you get the plugs?
     
    #2 bisco, Feb 21, 2026 at 1:51 PM
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