AskPatty Certified Female Friendly Logo
Hi Patty and experts—I have a 2001 Toyota Celica GTS with 201,000 miles. I've done all of the standard maintenance over the years and have never had the "Check Engine" light come on until this week. I hooked up a OBDII and came up with P0420 01/01. I see this is "Catalyst System Efficiency Below Threshold (Bank 1)". In this hot, rainy summer in the mid-Atlantic, my car unfortunately seems to run best WITHOUT the AC on so I suspect it may have to do with that. I'm still get great gas mileage and the car isn't making any odd noises. I do have a good mechanic but I want to make sure I know a little before going in. I also prefer not to pay too much :-)

Contribute to this question:


blog comments powered by Disqus

Related Toyota Celica FAQs


  • Car has normal rev when check engine light is on, but goes much higher when engine light ... Read More
  • I have a 2003 Toyota celica and the car is starting up and running perfect but the check ... Read More
  • My Toyota Celica instrument panel lights start to flash and the engine dies while ... Read More
  • About my son's 2000 Toyota Celica. Yesterday he went down the street to the corner store, ... Read More
  • Why is my check engine light on after I replaced the clutch on my 2002 Toyota Celica gts? Read More
  • All the electrical system stopped working on my Celica gts, the dash doesn't work at all ... Read More
  • My 1993 Toyota Celica GT has lost power, when I was accelerating. I had the gas pedal to ... Read More
  • I bought a used 1996 toyota celica with the engine running ,when i turn on my lights ... Read More
  • Hi. I own a 2002 Toyota Celica. She has been my baby for 5 years, but because I've had 2 ... Read More

Need Car Advice?

Ask The Experts!

Find Cars For Sale

Help Our Charities