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Service bulletin EG00299

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id606212
Published by NHTSA1999-08-12
Manufacturer's numberEG00299
Manufacturer's date1999-06-11
NHTSA componentENGINE AND ENGINE COOLING:ENGINE:GASOLINE

NHTSA's summary

REVISED INFORMATION TO ASSIST IN THE DIAGNOSIS OF DIAGNOSTIC TROUBLE CODE P0420 INDICATING A POSSIBLE CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD CONDITION. *TT

The document

No address for NHTSA's copy can be built for this communication. Ask the dealer for it by the manufacturer's number.

Components

Engine

Trouble codes named

P0420

Vehicles listed
TOYOTA SIENNA1999

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Other bulletins for the same vehicles and component
T-TT-0010-10 Rev2018-04-02. Service bulletin. Tech Tip: Low battery voltage can contribute to a MIL "ON" condition for P0335 (Crankshaft Position Sensor Circuit) and/or P0340 (Camshaft Position Sensor Circuit) due to inconsistent rotational speed of the engine's crankshaft.
46122005-08-04. Service bulletin. DIAGNOSTIC - ENGINE REPAIR MANUAL CORRECTION. 00400-RM657-U. *TT
037042004-11-03. Service bulletin. ENGINE BANK 1 AND BANK 2 A/F AND 02 IDENTIFICATION. VARIOUS TOYOTA MODELS. *TT
008042004-05-26. Service bulletin. MALFUNCTION INDICATOR LAMP ON 1MZ-FE ENGINE MISFIRE DIAGNOSTIC TROUBLE CODE (DTC) P0300, P0301, P0302, P0303, P0304, P0305 OR P0306. *TT
TC020022002-03-19. Service bulletin. SPECIAL POLICY ADJUSTMENT REGARDING VEHICLES EXPERIENCING ENGINE OIL GELLING OR SLUDGE. *TT
EG013992000-04-14. Service bulletin. SOME VEHICLES MAY EXHIBIT A ROUGH IDLE, AND OR A MALFUNCTION INDICATOR LIGHT ON CONDITION IN WHICH A SINGLE CYLINDER MISFIRE CODE, OR CODES ARE PRESENT. *TT
EG001002000-04-14. Service bulletin. SOME CALIFORNIA EMISSION SPECIFICATION VEHICLES MAY EXHIBIT A ROUGH IDLE AND OR A MIL ON CONDITION IN WHICH A SINGLE CYLINDER MISFIRE CODE OR CODES ARE PRESENT. *TT
EG002991999-05-11. Service bulletin. SOME VEHICLES MAY EXHIBIT DIAGNOSTIC TROUBLE CODE P0420 INDICATING A POSSIBLE CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD CONDITION. *TT