(98 Legacy GT 2.5 107K) This thing has been nickeling and diming me since the HG's went about 2 months ago. Airbag light just came on, have to bring it in to the dealer, BS price to just read the code, but that's besides the point, Caliper locked up the other day, and all of a sudden my inner passenger side CV Joint boot ripped, and oil pan started leaking! I refuse to but anymore money into this. Now my cat is triggering this P0420 code. I understand that this is most likley caused by the front 02 sensor and not a bad cat. The thing is my rear cat is rattling inside like a bunch of broken metal. If you tap on it with your hand you can hear it. It's friggen anoying as hell driving it to. I'm thinking about just hollowing it out. Would anything bad happen other then more pollution? I dont have to pass an emission tests. Would this clear the code, leave the code or make the car run worse. I am getting worse gas millage since It popped the code, my private garage mechanic thinks there shouldnt be a big deal by hollowing that out. If I still have a code then replace the front 02? Or will a hollow cat cause the 02 sensor to run a code, or make he car run leaner or richer or whatever it does? I figured if I hollowed out the cat, and removed the debri that's in the way, and then replaced the front 02 sensor if the code didnt go away, that It should be good to go. Or am I missing something here? I know I've done this with other makes and the car actually ran better, however, this is a subaru, and Im just not sure what hollowing out the cat would do.

Well congratulations, your the 2% that actually has a bad cat.

 

i REALLY cant advise you what to do *looks innocint*

 

But

 

 

If the cat is rattling its shot and clogged up, and can account for the poor gas mileage, and probab;ly some decrease in performance.

 

Since its only one cat right now, just *diagnose* one at a time.

 

at your mileage a Oxygen sensor wouldnt be out of the question.

 

nipper

LOL I seem to be the 2% that has everthing go out on me. The damn car still runs and drives too good to let it just rot away. Still handles like a dream.

Welcome to my world. I am the one half of one percent that gets all those wonderful side effects from medictaions.

 

 

As i tell my Dr, why cant i also be the one half of one percent that hit the lottery....

 

 

nipper

If it wasnt for bad luck, I'd have no luck at all. But hey looking on the bright side, I've replaced so much ************ on that car theres nothing left to fix! So without saying, hollowing out that back cat, and seeing if that fixes the code would be the way to go? And if not then replace the front o2? Or will having a hollowed out cat with a new 02 sensor still throw the code? I can live with the CEL, (a little electrical tape works) as long as it's meaningless. My 96 couger had the CEL light on same deal o2 sesor in rear cat, dealer said it's not doing anything bad, nor is your car suffering from it, its a known problem and what they could do was put in a dummy plug just to stop the CEL from showing. Didnt waste the money after I knew the car was fine.

 

Welcome to my world. I am the one half of one percent that gets all those wonderful side effects from medictaions.

 

 

As i tell my Dr, why cant i also be the one half of one percent that hit the lottery....

 

 

nipper