The owner's book on my 98 C230 says the federal Emissions warranty is 2yrs/24,000 miles, except for starred items which are waranteed to 8 yrs/80k miles. The MAS wasn't a starred item in my 1998 book. For CA and Massachusets, the emissions warantee for everything, including the MAS, ECU, etc. is 7/70. You might check your 1997 books to see if anything was different for you (ie. mas included on the 8/80 fed emissions warantee?)

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John

2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)

Click to see 87 300E