Chevrolet Repair: CHEVROLET SUBURBAN 2500 1994, 5.7 L, vacuum leaks, chevrolet suburban

Question
THIS CAR IS BURNING TOO MUCH GASOLINE LESS THAN 10 MI /GAL.
EXHAUST FUME LOOK NORMAL BUT ABUNDANT
COLD STARTING GOOD
POWER AVAILABLE IN ALL REGIMES
WHAT I SHOULD LOOK TO TO REDUCE SIGNIFICANTLY THE CONSUMPTION OF GASOLINE?
THANK YOU
FRANCOIS

Answer
Hey,

 Have ignition timing checked first off.  Then scan it for codes and make sure you have a good oxygen sensor.  Check for vacuum leaks under the hood but it wouldn't hurt to install a new primary 02 if youcan't check it. They don't last forever and are the leading cause of fuel economy problems.

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