How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Chad Farhat Your Own Question
Chad Farhat
Chad Farhat, ASE Certified Technician A6 - Electrical / Electronic systems A7 Heating / Air conditioning systems
Category: Toyota
Satisfied Customers: 2775
Experience:  Owner at Carolina Auto Service & Sales , 20 years Experience in Foreign & Domestic vehicles
45790705
Type Your Toyota Question Here...
Chad Farhat is online now
A new question is answered every 9 seconds

Its give a P0420 code catalyst system efficiency below

Customer Question

its give a P0420 code catalyst system efficiency below threshold (bank1) its A 2012 CAMRY SE
JA: Just to clarify, what's the exact code? And have you tried to reset it?
Customer: YES IT KEEPS COMING BACK
JA: Are you fixing your Camry yourself? What have you tried so far?
Customer: NOTHING BUT THEY SAY I HAVE TO CHANGE THEVCATALYST
JA: Anything else you want the mechanic to know before I connect you?
Customer: NOTHING
Submitted: 2 months ago.
Category: Toyota
Expert:  Chad Farhat replied 2 months ago.

Hi, I'm Chad. Welcome to JustAnswer. I'm reviewing your question and I will be posting your reply ASAP.

Expert:  Chad Farhat replied 2 months ago.

Hey how are you

how many miles on it now ?

was it misfiring with check engine light on flashing and you drove on it ?

it is true the catalytic could be the issue, there is also 3 more possibilities ,i would like to think they checked and then came up with results as cat ids bad ,did they ?

please click on the link to view

2GR-FE ENGINE CONTROL: SFI SYSTEM: P0420, P0430: Catalyst System Efficiency Below Threshold (Bank 1)
P0430 - Catalyst System Efficiency Below Threshold (Bank 2)

MONITOR DESCRIPTION

The ECM uses sensors mounted in front of and behind the Three-Way Catalytic Converter (TWC) to monitor its efficiency.

The first sensor, the air fuel ratio sensor, sends pre-catalyst information to the ECM. The second sensor, the heated oxygen sensor, sends post-catalyst information to the ECM.

In order to detect any deterioration in the three-way catalytic converter, the ECM calculates the oxygen storage capacity of the three-way catalytic converter. This calculation is based on the voltage output of the heated oxygen sensor while performing active air fuel ratio control.

The oxygen storage capacity value is an indication of the oxygen storage capacity of the three-way catalytic converter. When the vehicle is being driven with a warm engine, active air fuel ratio control is performed for approximately 15 to 20 seconds. When it is performed, the ECM deliberately sets the air fuel ratio to lean or rich levels. If the cycle of the waveform for the heated oxygen sensor is long, the oxygen storage capacity is great. There is a direct correlation between the heated oxygen sensor and the oxygen storage capacity of the three-way catalytic converter.

The ECM uses the oxygen storage capacity value to determine the state of the three-way catalytic converter. If any deterioration has occurred, the ECM illuminates the MIL and stores the DTC.

This system determines the deterioration of the entire catalyst system (including the front and rear catalysts), by using the oxygen storage capacity value of the front catalyst, that is more sensitive than the rear catalyst, as the representative value. Therefore, be sure to replace the front and rear catalysts together when catalyst replacement is necessary.

Zoom and Print Options

Please let me know

Thank You

Chad Farhat

ASE Certified Technician

Expert:  Chad Farhat replied 2 months ago.

Please let me know if you need anything else on it, just reply back and we will continue

If you are good, Please Kindly Rate Me.

A 5 Star Rating is much Appreciated

If you feel I have not been helpful Please DO NOT RATE ME BAD OR POOR (1 or 2 stars) ,You can always ask me again or I can opt out of your question & open it for another expert ,that will provide you with more or better assistance on this issue

Please keep in mind that when you rate me , it does not end our conversation.

you can always come back to this conversation and ask me any follow up question you may have on this issue

(you can copy this link page & paste it in your browser when ready and it will open up our conversation again)

Thank You
Chad Farhat
ASE Certified Technician