2002 Toyota Sienna 2002 Toyota Sienna fault code P0420

Tiny
TALTOS
  • MEMBER
  • 2002 TOYOTA SIENNA
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 171,500 MILES
I failed my emmisions test. The error code reads P0420: catalyst system efficiency below threshold (bank 1). I have been told this is o2 sensor behind manifold near firewall and that the old ecm should be replaced with a new one because this was a problem the ecm's had that toyota fixed. What say you?
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Tuesday, February 17th, 2009 AT 11:53 AM

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Tiny
MERLIN2021
  • EXPERT
I say it could be the ECM, this is the tech bulliten on it.
Reference Number(s): EG047-05, Date of Issue: October 19, 2005 Related Ref Number(s): EG047-05 ARTICLE BEGINNING INTRODUCTION Under certain driving conditions, some 2001 - 2003 model year Sienna vehicles may exhibit a M.I.L. "ON" with the following DTC: P0420 (Catalyst System Efficiency Below Threshold [Bank 1]) The Engine Control Module (ECM) (SAE term: Powertrain Control Module/PCM) logic has been modified to improve this condition. APPLICABLE VEHICLES 2001 - 2003 model year Sienna vehicles. PARTS INFORMATION PARTS INFORMATION WARRANTY INFORMATION WARRANTY INFORMATION Applicable Warranty*: This repair is covered under the Toyota Federal Emissions Warranty. This warranty is in effect for 96 months or 80,000 miles, whichever occurs first, from the vehicle's in-service date. TOYOTA: 2001 - 2003 Sienna SECTION: ENGINE PREVIOUS PART NUMBER CURRENT PART NUMBER PART NAME QTY 89661-08061 89661-08062 Module, Engine Control 1 89661-08070 89661-08071 89661-08080 89661-08081 OP CODE DESCRIPTION TIME OFP T1 T2 895011 R & R Engine Control Module 0.5 89661-08061 89661-08070 89661-08080 8A 71REPAIR PROCEDURE 1. Verify DTC P0420 with the Diagnostic Tester by referring to the Technical Information System (TIS), 2001 - 2003 model year Sienna Repair Manual: Diagnostics: Engine: Pre- Check. 2. Replace ECM (PCM). Follow the Repair Manual ECM replacement instructions. Refer to TIS, 2001 - 2003 model year Sienna Repair Manual: Introduction: How To Troubleshoot ECU Controlled Systems: How To Use The Diagnostic Chart And Inspection Procedure. 3. Perform the following steps to confirm that the vehicle is repaired. A. Reset the Readiness test by using the "Clear DTC" function on the Diagnostic Tester. To clear the DTC, refer to TIS, 2001 - 2003 model year Sienna Repair Manual: Diagnostics: Engine: Pre-Check. B. Perform Readiness Monitor Drive Patterns for Catalyst Monitor O2S type and AF Sensor type. Refer to TSB No. EG003-02, "Readiness Monitor Drive Patterns, " procedures: Catalyst Monitor (O2S Type) and Catalyst Monitor (AF Sensor Type). C. If a DTC is set during the above drive patterns, refer to the Diagnostic Trouble Code Chart in TIS, 2001 - 2003 model year Sienna Repair Manual: Diagnostics: Engine: Diagnostic Trouble Code Chart. Test drive the vehicle to confirm normal operation.
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Tuesday, February 17th, 2009 AT 12:09 PM
Tiny
TALTOS
  • MEMBER
So if I read this right I have 171,000 miles on a 2002 so I can not get it fixed by Toyota at thier cost?
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Tuesday, February 17th, 2009 AT 12:25 PM
Tiny
JCASTRO20111
  • MEMBER
This worked for me to pass inspection in GA with the buggy ECM described in the TSB above:

What is required: Code Reader (about $50 from amazon)

1. Disconnect the battery from the car a while
2. After a while (I did it for a day, might not take nearly as much time) reconnect the battery. If your check engine light was on, and now it is not, you did it for enough time.
3. Plug in your code reader. And drive your car for a while (some highway and some city driving)
4. Keep an eye on the monitors from the code reader. As you drive, you will see that different monitors go from a "Not Ready" status to a "Ready" status. You will want to keep driving until all but the Catalyst monitor are either in the "Ready" or "Not applicable" status.
5. Once the only "Not Ready" monitor is the Catalyst monitor, take it in to inspection right away. In GA, you are good to go if only 1 monitor is in "Not Ready" status and the Check Engine light is not on.

Check with the local emissions rules to determine if your car can pass if any of your monitors are in "Not Ready" state.
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Tuesday, January 13th, 2015 AT 7:25 AM

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