So, I'm getting the 420 code continuously now in my '02 OBW. Not really wanting to dump the $$$ into a new cat until I'm more confident that I'm not running rich for as-yet-unknown reasons, precipitating the code and/or killing the cat.

 

However, suddenly I have a chance to get an OEM subie cat with very few miles on it, for very little $$$. Only problem is: it's OE for an '05 Outback XT (which is, sadly, recently totalled). My car is an '02 Outback.

 

So...any chance these two cats are compatible? As I cannot inspect the '05 unit 'till end of next week, but have to decide now, I've got three questions:

 

1) Is it, by any chance, plug-and-play, as far as fitting it, or would I have to weld?

 

2) Would the O2 sensors be compatible. Like, could I screw mine into that cat (they are both new), or are they a different size? Or alternatively, could I use the O2 sensors that come with the '05 cat; would they get along with my '02 ECU?

 

3) Would the function of the cat be compatible with my engine/ecu? Pretty much the same engine, so I'm thinking yes. Key point being: will it NOT set the 420 (cat efficiency) code?

I have no idea about the answer to your question, but have you tried changeing your O2 sensors, usualy changing the front sensor solves the problem some times the back one needs to be changed to. It seems very odd for a 2002 to need a new cat. I have an 01 with over 125k on it, it threw the P00420 code at around 105k and a new front O2 sensor solved the problem.

And my 99 also threw that code at about the same mileage. New front ox sensor also solved it. About $60 and ten minutes to install.

#1 - replace the o2 sensor, seems to be a spat of these going on, including mine. We replace the o2 sensor and problem solved.

 

#2 - i dont think it will. i think there was an emissions change, and the older car may run too rich for the newer cat, not sure.

 

nipper

Don't think it's even close. If I remember those, the up pipe to the turbo has the 1st cat, and the down pipe the 2nd. Also the rest of the exhaust on the turbo are 1/2" to 1" larger, flanges and all. Non of the exhaust is interchangable.

Ok, not sounding likely.

 

I did replace my front O2 sensor with an oem one.

 

Still getting the code. Still having some driveability issues (hesitation on takeoff, occasional, but not often at all: what feels like misfire, weird rough acceleration, and due to the above: tough to drive smoothly in stop/slow and go traffic).

 

Haven't replaced the rear O2 sensor. Could that be my problem?

Ok, not sounding likely.

 

I did replace my front O2 sensor with an oem one.

 

Still getting the code. Still having some driveability issues (hesitation on takeoff, occasional, but not often at all: what feels like misfire, weird rough acceleration, and due to the above: tough to drive smoothly in stop/slow and go traffic).

 

Haven't replaced the rear O2 sensor. Could that be my problem?

 

sure its those little details...

 

dont replace the cat yet, fix th other problem first. When was the last time this thing had a tune up and fuel filter change. Could be a dirty MAF sensor.

 

nipper

go to an auto parts web site and search for o2 sensors for both the '05 and the '02. if they are the same and they maybe, can you get the cat for less than the new sensor? if its cheaper , and the sensors are compatible. get the used cat, swap the sensor and then decide what to do with the cat, sell swap or scrap.

sure its those little details...

 

dont replace the cat yet, fix th other problem first. When was the last time this thing had a tune up and fuel filter change. Could be a dirty MAF sensor.

 

nipper

 

Filters (air, fuel, oil) and tuneup (plugs, wires, clean IAC, clean throttle body, new front O2 sensor). ~2000 miles ago. Car has 107,000 miles. Shop recently diagnosed/replace bad neutral switch (def'y helped, but still have some issues), and adjusted throttle (was not opening and closing quite all the way). Getting the 420 much easier/quicker since neutral switch (makes sense, since nuetral switch off is a precondition for cat readiness).

 

So...pretty sure I have no MAF, just a MAP. That had occurred to me, but thinking idle would be wacky if MAP were bad. My idle is pretty steady. Do you still think it's possible?

 

One thing: recently I was setting up a tent, after driving for hours, on a cool night. So, engine off, key on, headlights on, and...my radiator fan stayed on **way** longer than I'd expect. Got me thinking about my coolant temperature sensor. What symptoms would I look for if that were bad?

Dang,

 

I see you are in Colorado. I was thinking we could swap a couple parts off mine to see if we could locate the problem. I guess that's not an option.

i almost want to say the diagnostic plugs are connected under the dash. When those are connected the cooling fans will run all the time and the car will run very oddly.

 

hrmmmmmmm

 

nipper

i almost want to say the diagnostic plugs are connected under the dash. When those are connected the cooling fans will run all the time and the car will run very oddly.

 

hrmmmmmmm

 

nipper

 

Hmmmmmmm indeed. If that's it, I'll piss my pants. And owe you some beers.

 

So...I've heard of these diagnostic plugs, but never come across them. Can you help me find them? (green and white? under the passenger side? or...?)

also the fan would run continously even with the engine off if the A/C were set to on or if the fan control knob were set to defrost

not mine (yes i pluged mine in once) they only ran when the car was on.

 

nipper

 

PS i like microbrews