Previous Thread
Next Thread
New Reply
Print Thread
Rate Thread

Joined: Nov 2002
Posts: 489
Senior Member
2002 Toyota Celica GT
Senior Member
2002 Toyota Celica GT
Joined: Nov 2002
Posts: 489
Ok, so I'm driving down interstate and my CEL comes on. Not the first time in the past month. But I did stop this time to get it checked.

Code P0420 - Catalyst System Efficiency Below Threshold (Bank 1)
-Gas leakage on exhaust system
-Open or short in heated oxygen sensor circuit
-Heated oxygen sensor
-Three-way catalytic converter

My car only has 63,xxx miles on it. The AutoZone guy suggested the O2 sensor. Any one else get this code? What can be done to test the different aspects of the possibilities and how can I fix it?


[Linked Image]
"Everything that has a beginning, has an end."
-The Oracle

Joined: Dec 2004
Posts: 15
Member
Member
Joined: Dec 2004
Posts: 15
I had the same code after i installed my TRD exhaust. One of your o2 sensors needs to be replaced or it has caused a minor leak around that vacinity. My problem was that my brother stripped my o2 sensors threads and it was leaking air at that port throwing that very same code. Luckily he is a engineer and borrowed a tool and die kit from work and retapped it. No problems since.

Joined: Dec 2004
Posts: 400
Senior Member
2002 Toyota Celica
Senior Member
2002 Toyota Celica
Joined: Dec 2004
Posts: 400
Get a scanner that can read the O2 values while the engine runs. Let the engine temp rise and check the voltage fron the O2 with the scanner. If there is voltage than you can scratch the short/open in the circuit.


If I'm not mistaken, Isn't the emission systom on this car covered under a 100,000 Mile warranty??? confused

Joined: Jun 2004
Posts: 1,694
Metal Storm 2040
2000 Toyota Celica
Metal Storm 2040
2000 Toyota Celica
Joined: Jun 2004
Posts: 1,694
yeah i've been running my GTS with cel on for like a month now with 6 thrown codes as well as the one mentioned in this thread. confused confused

Join the conversation - Register Now or Log In to add your comment


Link Copied to Clipboard
Member Spotlight
Aerowilson182
Aerowilson182
2001 Toyota Celica GT
Auburn, AL

Posts: 260
Joined: August 2004
Thank you.: Props to Zen Motorsports for an outstanding job on the Turbo fabrication, and Props to Hass Autoworks for hooking me up with so many sweet parts, You guys Rock!
Random: "To give anything less than your best is to sacrafice the gift" ~Prefontaine
Show All Member Profiles 
Recent Topics
Spyder Headlight LEDs
by Dxnxld - Mar 25, 2024 6:51am
Anyone ever hear this noise?
by CeliacCelica - Mar 21, 2024 10:51am
Clunking sound (not sure where from)
by Juliansky - Mar 20, 2024 3:01am
Does anybody know where i can find a S53 trans rebuild kit?
by MoreRamenNoodles - Mar 19, 2024 8:57pm
Urgent
by SoloXKay - Mar 19, 2024 11:58am
OEM speedometer on aftermarket ecu
by Penaman99 - Mar 5, 2024 11:23am
Brake master cylinder
by Nigel100 - Mar 5, 2024 2:45am
newly purchased 2000 GTS
by CantShift - Feb 27, 2024 9:06pm
Customize Your Toyota Celica Privacy Policy · About · Contact
Privacy Policy · About · Contact
CelicaHobby.com is an independent Toyota Celica enthusiast website. CelicaHobby.com is not sponsored by or affiliated with Toyota Motor Sales, USA, Inc. in any way. The Toyota and Celica names and logos are trademarks owned by Toyota Motor Sales, USA, Inc.
© CelicaHobby.com, 2001-2024
Powered by UBB.threads™ PHP Forum Software 8.0.0
(Preview build 20230331)