Join Date: Nov 2011
Car: 01 Outback H6 VDC, 97 GT wgn w/ ej22, 98 OBW w/ej22
Feedback Score: 0 reviews
subaru cats are very very good and last a long time. most all subarus go to their deaths with factory cats.
ther are lots of other things that will cause poor gas mileage before the cats will. and i think ''clogged'' cats will cause a power, bogging down, problem. so look somewhere else, cheaper, first.
i would start with a tune up, NGK plugs and subaru, or really high quality wires. plus oil , air filters.
knock sensor will cause the mpg to plummet and it will do this before it throws a code. but if left un-addressed long enough it will eventually throw a code.
o2 sensors can get old and cause bad mpg, before they throw a code. and these are cat related. the front one needs to be a subaru product, the rear one can be generic.
do you have any trouble codes? is the CEL on?
what makes you think your cat is clogged?