I tend to think like m.b.doc, I replace the air fitler every year, about every 22k miles. I clean my maf with maf cleaner when I do the air filter. I don't worry about replacing things just because they are bosch, ever own a german car with a Lucas electrical system? I do tend to follow the maintenance schedules, adding a coolant flush every two years, and a tranny service at the same time. Most computer controled cars will run without a maf, or with it unplugged, I spend time thinking about single failure components more.

Best wishes, Chuck

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2000 C230 Kompressor "Frosty"

2007 PT Cruiser
2001 VW TDI Beetle
1999 Landrover Discovery II
1971 Corvette

Gone: 97 Cabrio, 83 240D, 93 VW Eurovan, 95 Volvo 850, 93 Chevy Astro Van, 77 VW Bus, 99 VW Jetta, 74 VW Bus