I bought a 05 Legacy i 2.5 usa made w/110,000 6mo ago. The CEL came on and cruise controll light blinks within two weeks of owning.I had OBD read. P0420 code Catalyst System (bank1).I replaced it with a new $147 02 sensor.Didn't work.CEL still on. I don't know what to do with it now.Still reads P0420.

 

Last week we had snow.I drove it to work.Didn't make it.Tried it in lower 2&3 gear Didn't help.No AWD.Front right wheel spins.I got on here reading about AWD.The oil temp light dose NOT blink,it dose NOT bind in tight turns,NO noise in Tranny,Shifts quite and easy,No fuse in FWD.I got out next day and double check right front wheel with left rear wheel. Rear wheels don't spin. It has a bad front left wheel bearing tho.(getting it fix this week $200) I took it to a tranny shop.They checked for tranny codes.Only found P0420.History showed both speed sensor coded at some time but not now. Rear wheel will spin in reverse,in gravle Tranny shop said.I'm worried I'm faceing some big repairs, Any Ideals??Where to start??I don't want to repeat the $147 didn't fix it thing again.Thank you for your suggestions. Jamie:banghead:

I've had the 0420 for the past year or so. Started at just about the same mileage.

It generally means the passenger side cat converter is heading south.

Saving numerous trips to local Autozone to have the code cleared each time, I bought a cheap $20 code reader/clearer from ebay and played around with the spark plug cheater trick (search 0420 code on this site). Unfortunately, our 2005s don't seem to like the cheaters and didn't 'fix" the problem.

The code doesn't affect drive-ability. I too replaced the front O2 sensor but that didn't help.

The code comes and goes so the "threshold" may be a little to tight in the computer's spec.

The blinking cruise control goes along with the code which apparently becomes inactive with the CEL.

Passing state state emission tests is tricky but after I clear the code and the car runs a particular set of cycles/speed runs and all systems are reading as "ready", I have been able to pass before it threw the code again.

I have read that there are some performance companies that will reformat the computer to eliminate this parameter but I haven't bothered with it (cost/benefit $300 versus replace the cat $700 after market which gets pricey itself and some say doesn't prevent the code from coming back).

Sorry to hear you are facing these headaches with your "new" car but quite possibly the previous owner had just reset the light before selling it to you.

Edited January 29, 201214 yr by brus brother

Thanks Brus Brother for you input. I will have to let it go till the AWD is fixed any way.I think the used car lot knew about the problems and sold me a bad car. It least I live in Tennessee.No inspections!If it rolls it is ok with them.But live and learn and pay pay pay.I wondered if the computer was causing the AWD to not work because of it throwing the code all the time? Or because the bad wheel bearing? It just makes me sick. Thanks!