I have an '89 LeSabre with 156,000 miles. It runs fine, but the
mileage is off. Normally I would get over 25 on normal trips and
29+ on the highway. Several months ago, when the mileage was
dropping, I changed the oxygen sensor, the fuel filter, and the spark
plugs. It was OK for a while, but the mileage was off soon after
that. I had it scoped and the mechanic said that the air flow
sensor might be a bit off, but the plugs were white, showing a lean
mixture. He also said he could get a sensor for around
$200.00. This is the only real problem I have had since buying
the car in "94. I change the oil regularly and the tires are all
at the correct inflation. Anyone have an idea?

plug wires, pcv, air filter, lucas fuel treatment, take off the ign control module and clean the ground plate. corrosion can hurt performance and effeciency

I had it scoped for the third time, and this time the mechanic said
that the fuel pressure regulator was putting out too much pressure, and
therefore too much fuel was going into the cylinders. The testing
also showed that the O2 sensor had been changed. When I changed
the sensor, the parts people recommended a lesser priced sensor over
the Bosch, saying that the sensors were made to the same specs and
therefore should perform the same way.

I HAVE A 93 LeSABRE AND I HAVE NOT BEEN ABLE TO FIND MY PCV, I BOUGHT ONE AND HAVE IT IN THE PACKAGE, BUT CAN'T FIND WHERE IT IS LOCATED. AM ALSO LOOKING FOR THE LOCATION OF THE FUEL FILTER FOR AN 89 ELECTRA PARK AVENUE, I CAN'T FIND ANYTHING THAT LOOKS LIKE THE ONE I PURCHASED TO REPLACE IT, I CAN'T EVEN FIND ANYTHING THAT LOOKS LIKE A FUEL FILTER. ON THE 93 IT WAS OBVIOUS SINCE THE FUEL FILTER WAS LEAKING AND EASY TO SPOT, NOT SO EASY TO REPLACE.