Service bulletins for the 1999 Toyota Sienna
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.
101 on file from NHTSA, as of 2026-10-19.
About P0420 on the 1999 Toyota Sienna: what the code means, and the bulletins and recalls about the same components.
By type
By component
By trouble code
Only bulletins with trouble code: P0420 are shown. Show all
| EG00299 | 1999-08-12. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:GASOLINE. REVISED INFORMATION TO ASSIST IN THE DIAGNOSIS OF DIAGNOSTIC TROUBLE CODE P0420 INDICATING A POSSIBLE CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD CONDITION. *TT |
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| 031199 | 1999-06-03. Service bulletin. UNKNOWN OR OTHER. BRIEF INFORMATION REGARDING DIAGNOSTIC TROUBLE CODE P0420 INDICATING A POSSIBLE CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD CONDITION. *TT |
| EG00299 | 1999-05-11. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:GASOLINE. SOME VEHICLES MAY EXHIBIT DIAGNOSTIC TROUBLE CODE P0420 INDICATING A POSSIBLE CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD CONDITION. *TT |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.