>>698373Was helping a friend with car issues recently and the helpful O'Rileys guy gave me the lowdown.
1. If the engine is installed poorly(mine had a brand new shop rebuild and same with the transmission) or coolant is somehow allowed to leak into the exhaust it will kill the cat.
2. If the check engine light is on, the Fuel control modual reverts to its base mix which costs about 3mpg in efficiency and will kill the cat In a few thousand miles(another think i wish i had known back in Salt lake)
3. If the check engine light comes on and the code pops up for the cat(p420) then, get it turned off. Subaru set the emission tolerances even tighter than Ca requires at 70ppm rather than 100 ppm.
4. If it comes back, get your o2 sensor checked/replaced($62 part)
5. If it comes back again, run some cat cleaner through it.
If it comes back again than one of the two(!?!?) cats may be bad and can be individually tested
6. If you have a bad cat, replace it with a $400 oem or >$200 aftermarket cat.
All in all, very happy with my lil outback. I can sleep in the back and haul alot of gear. There is room for me to sleep and 5 of the big black costco storage boxes. I really want to mod it out as a wasteland vehicle(lift kit, scoop, tow package, snorkel, roof rack) but right now it is the perfect low profile urban camouflage.