Question about 1999 Lexus RX 300

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Loud engine or Muffler

I always use 93 or 95 High octane gas. Thursday leaving the office for an appointment I put $10 bucks of 7-11 Citigo gas in tank. By Friday night car sounded like it was a mack truck.Loud Loud and Check Engine lights been flashing! Stopped at an Auto Zone-picked up Lucas cleaner and did a partial fill with Mobile high test gas.

side note --
When I took vehicle over to Lexus for 90,00 mile service I was informed the Check Engine light has to do with a sensor. Also that I have crack in my muffler.

Overall the vehicle runs good -the loudness of engine concerns me though. Do you recommend I replace the muffler?


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  • connectorder May 17, 2009


    Thanks for the prompt response!

    I will definitely check into this muffler ASAP




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Hi. if the muffler is truly cracked, it will release a loud, unfiltered, noise during acceleration and idling as well. it will rattle as well. i recommend replacing the muffler ASAP.

Concerning the fill up at 7-11, there may have been a high water content that was in this gas stations tank and, this was transferred to your tank during the filling. the Lucas treatment will remove the water out of the tank and correct any damage that may have occurred,if any..

Posted on May 16, 2009


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Posted on Jan 02, 2017


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