P0420 TWC System Low Efficiency Bank 1-A

P0430 TWC System Low Efficiency Bank 2-A

also saying that my right rear tire is flat.. and suggestions.. im going to try and reset the code right now.

 

Here's some info for you. I doubt both sensors went bad at exactly the same time. May be a connection to the PCM or the PCM. I'm sure others who know more will chime in.

P0420/P0430

Circuit Description
In order to maintain a reasonably low emissions of Hydrocarbons (HC), Carbon Monoxide (CO), and Oxides of Nitrogen (NOx), the engine controls system uses a three-way catalytic converter. The catalyst within the converter promotes a chemical reaction which oxidizes the HC and CO present in the exhaust gas. This reaction converts them into harmless water vapor and Carbon Dioxide. The catalyst also reduces NOx, converting it to Nitrogen. The PCM monitors this process using Bank 2 HO2S #2. Bank 2 HO2S #2, located in the exhaust stream past the three-way catalytic converter, produces an output signal which indicates the oxygen storage capacity of the catalyst. This determines the catalysts ability to convert exhaust emissions effectively. If the catalyst is functioning correctly, the Bank 2 HO2S #2 signal will be far less active than that produced by Bank 2 HO2S #1. This indicates that the three-way catalytic converters oxygen storage capacity is below a threshold considered acceptable.
When the conditions for running this DTC are met, the following occurs:


The PCM captures the current rear HO2S rich/lean status.
The Air Fuel ratio transitions from rich to lean or lean to rich depending on the capture rear HO2S rich/lean status.
The Air Fuel ratio transitions a second time opposite the first Air Fuel ratio transition.
The PCM captures the response time (the time the HO2S goes from below 300 mV to above 600 mV and from 600 mV to below 300 mV) of the front and rear Heated Oxygen sensors when the Air Fuel ratio transitions occurred.
The PCM measures the time it takes the rear HO2S voltage to cross a reference rich/lean threshold minus the time it takes the front HO2S voltage to cross the same rich/lean threshold. The time difference from the front and rear HO2S is the oxygen storage capacity of the catalyst. This DTC sets if the time exceeds a predetermined threshold.
Conditions for Running the DTC


No AIR, CKP, CMP, IAT, IC, MAF, MAP, ECT, TP, EVAP, Right Bank HO2S, Misfire, Right Bank Fuel Trim, Injector, VSS, Engine Protection, or Transmission DTCs are set.
The engine is operating.
The ECT is greater than 65°C (149°F).
The vehicle speed is less than 136 km/h (85 mph).
The throttle angle is greater than 10%.
The engine speed is less than 4000 RPM.
The MAP is between 25 kPa and 80 kPa.
The air flow is between 14 gm/s and 40 gm/s.
The closed loop fuel control is enabled.
Conditions for Setting the DTC
The PCM determines if the oxygen storage capability of the catalytic converter has degraded below a calibrated threshold.

Action Taken When the DTC Sets


The PCM illuminates the Malfunction Indicator Lamp on the second consecutive ignition cycle that the diagnostic runs and fails.
The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure records.
Conditions for Clearing the MIL/DTC


The PCM turns the MIL OFF after three consecutive ignition cycles that the diagnostic runs and does not fail.
A last test failed (current DTC) clears when the diagnostic runs and does not fail.
A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
Use a scan tool in order to clear the MIL/DTC.

 

I found this website and it contains a section on codes and solutions, give it a try, it pretty extensive..

http://www.gearchatter.com/index.php

 

thanks guys.. i turned the codes off and nothing has come back yet.. driven it a good bit so..