Oil clogged pcv valve?
I've been getting below average mileage on my 92 SSE and decided to check the pcv valve. Should there be oil on it and in the housing it sits in? I've done a full tune-up otherwise...plugs, wires, new o2 sensor, gas filter ( all ac delco...no bosch). I just can't get more than 230miles per tankful on local driving. When I first got the car it was getting 270-280 per tankful. I average around 14-15mpg around town. On the highway the car gets 24mpg. Why such a radical difference? I am not a heavy footed driver. Why would my mileage decrease after a tune-up? I should have left it alone.