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

Engine burning oil - how to protect the cat?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by kkeane, Apr 5, 2017.

  1. kkeane

    kkeane Junior Member

    Joined:
    Apr 21, 2015
    72
    17
    0
    Location:
    San Diego
    Vehicle:
    2005 Prius
    Model:
    II
    My 2005 Prius is beginning to burn oil. Not much; it is pretty much normal after close to 150k miles; I'm not worried for the engine.

    However, burning oil tends to clog up the catalytic converter - my previous Prius eventually died from that problem at 300k miles. I am in California, where no third-party cats are available. The cost of an original Toyota cat rivals replacing the hybrid battery.

    Are there any preemptive steps I can take to protect the catalytic converter?
     
  2. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,525
    8,428
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    If the car is not burning much oil now, I wouldn't waste my energy worrying about it.

    You can replaced the pcv valve if you haven't already done so, it's a good preventive measure when you start noticing oil burning
     
  3. Samprocat

    Samprocat Active Member

    Joined:
    Jan 16, 2017
    491
    297
    0
    Location:
    Lincoln, NE
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    Yes.....depends on how much oil you are burning.....you should take car once a week on highway doing 65 or more for 20-30 minutes.....on this car's catalytic converter run between 1000-1250 degrees Fahrenheit.....considered that your O2 sensors are in good shape...O2 sensors should be inspected around 60 000 miles....and replaced past 80 000 miles......
    Hope this will give you idea


    Posted via the PriusChat mobile app.
     
  4. kkeane

    kkeane Junior Member

    Joined:
    Apr 21, 2015
    72
    17
    0
    Location:
    San Diego
    Vehicle:
    2005 Prius
    Model:
    II
    My previous Prius burned gas for about 100k miles until the cat died, and with the amount of driving I do, that's only about two years. That's where my concern comes from.

    Thanks for the tip on the PCV! My trusted car repair shop just closed, and I'm going to have to find a new one or do it myself.

    That shouldn't be a problem - I drive about 50 miles of freeway almost every day. Good point on the O2 sensors!
     
  5. Kahn Khan

    Kahn Khan New Member

    Joined:
    Apr 5, 2017
    3
    1
    0
    Location:
    Stockholm
    Vehicle:
    2007 Prius
    Model:
    N/A

    I am sorry but could you please tell me how can I post here?
     
  6. uart

    uart Senior Member

    Joined:
    Sep 7, 2009
    4,215
    1,202
    0
    Location:
    Australia
    Vehicle:
    2005 Prius
    While oil burning is one factor, the type of oil you use will definitely have an impact as well. Seeing as it is the phosphorus and sulphated ash content that is particularly damaging to the cat, then using a good quality modern low SAPs oil might help.

    While some of these oils are marketed toward modern diesels with particulate filters, they will also be protective for modern cats too. Look for an oil carrying a rating such as ACEA C1/C2/C3, or a dexos1 or ILSAC GF5 for example.
     
    m.wynn, JessO, SFO and 1 other person like this.
  7. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,855
    3,968
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    When you have posted 5 messages on various threads, you will see a "Start New Thread" button at the top right of each forum. You click on that button to start a new thread. You can blame spam bots for that posting limit.
     
  8. fotomoto

    fotomoto Senior Member

    Joined:
    Apr 22, 2009
    5,608
    3,788
    0
    Location:
    So. Texas
    Vehicle:
    Other Hybrid
    What about a used one from the junk yards? Are those legal?
     
  9. kkeane

    kkeane Junior Member

    Joined:
    Apr 21, 2015
    72
    17
    0
    Location:
    San Diego
    Vehicle:
    2005 Prius
    Model:
    II
    No, they aren't, although it would likely be more difficult to detect because they carry the correct sticker.

    There also are practical problems. For one, a junkjard cat is in unknown shape; it may be just as bad as the one you are replacing. For another, you won't get any legitimate car repair shop to install it. For a shop, the fines for installing one are astronomical.

    I hear that many Prius owners near the Arizona or Nevada borders take their car across the state line to get this done. That can be a viable option if you don't have to worry about smog checks (not all parts of California have smog checks), but it is another one of those options to avoid getting caught, as opposed to it being legal.
     
  10. kkeane

    kkeane Junior Member

    Joined:
    Apr 21, 2015
    72
    17
    0
    Location:
    San Diego
    Vehicle:
    2005 Prius
    Model:
    II
    Interesting. I always used one of the oil-change places to do it, so I never decided which oil they use. Maybe it's time to start doing my own oil changes...
     
  11. SFO

    SFO Senior Member

    Joined:
    Feb 7, 2017
    5,302
    4,241
    0
    Location:
    Northern California
    Vehicle:
    2007 Prius
    Model:
    N/A
    Did a little research and it looks like the ratings with the lowest sulfated ash content would be: ACEA C1, lowest SAPS (Sulphated Ash, Phosphorous, Sulphur) or ACEA C4, having low SAPS but a higher HTHS rating.

    Wonder how the API FA-4 rating stacks up against the above?

    And who carries ACEA C1 rated oil in the states?
     
    Fred_H likes this.