2000 intake

The garage that does some service on my blazer has suggested a new intake gasket as a preventivie measure. The tech said that they all leak and the use of a felpro gasket kit will prevent problems later on including ruined oxygne sensor. Price around $300
I asked him how he knew the gasket was defective. He said no gaskets are used on assembly at the factory and the original plastic compound is known to fail. The only driveability problem I can document is a 2-3 mpg drop in gas mileage that came on gradually at around 50K. The truck now has 70K and runs fine otherwise. Should I change the gasket?? Does the reduced mileage mean the oxygen sensors are already shot??? I have not yet done any tune-up service and have only kept up with the severe maintenance schedule in the factory manual. No engine warning lights yet. thanks

No, do not replace the gasket.

Replacing intake gaskets preventative maintanence? Ya right! NOT!

Time for a tuneup up bro including:

Plugs (AC Delco Plats)
Wires
Fuel Filter
Air Filter
Synthetic Oil Switch
Synthetic Tranny and transfer case and differential fluids.

I would do these before swapping any gasket or O2 sensors.