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Are the two cats identical parts? Reason I'm asking is 1stsubaruparts.com only sells the front one. There's nothing listed under 'rear'. So I wondered if the part for front and rear are identical.

 

Anyway, last night the CEL went back out, so now what?

 

I was thinking of asking a mechanic to remove the 02 sensors and see if they are fouled.

 

On my car (96 MY) there are two distinct and separate cats. But later on (I don't know exactly when) Subaru began installing two cats in a single unit, meaning you cannot buy them separately. You could of course have a muffler shop install just one of them by cutting and welding.

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Heyall... I recently got the P0420 code along with P0303, P0304 and P0325. I knew the plugs were far gone (gap was near 0.050" and supposed to be 0.039"), and replaced them. Misfires happened when cold, going up hill, so the plug replacement logic is clean. Cleared all codes, but the P0325 keeps returning.

 

After clearing codes, the knock sensor throws a CEL (P0325) once the engine is hot (the last time about 40 miles after a clear). I've cleared the P0325 repeatedly, so the knock sensor is getting replaced tomorrow. I've read elsewhere that the knock sensors exhibit failure when hot, and maybe look ok when cold.

 

It seems like clearing that one code clears the Catalyst effeciency confirmation check as well, and since I was getting the car inspected, the Catalytic Converters (CC's) showed up as not ready. Had to mumble to the garage guy that I'd disconnected the battery or such B.S. This guy is new to me, and if I mention to him I got a P0420, I don't want him holding me up for a CC replacement, since I'm pretty sure the P0420 came from a CC polluted by bad plugs. The P0420 has yet to reappear in 200+ miles.

 

Question is, who knows how long / many driving cycles / under what conditions Subies need to recheck the CC efficiency? The garage won't issue my inspection until he reads Catalytic Converters / HO2S / etc, ready.

 

Once I replace the failing knock sensor, I'd like to get the inspection done quickly, since I'm out of date. Knowing what driving conditions are needed to recalibrate the CC check could save me some time and headaches. TIA, B.

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In my FSM for 1996 ( I suspect same for other years), it says the CEL comes on after «two consecutive trips with fault». For P0420.

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Well, the CEL went out, and last night it came back on. I haven't been to check the code yet, but I *bet* it's P0420.

I changed the plugs, wires, fuel filter last year. o2 sensors year before last.

I guess my next step will to replace the CC. I don't want to, but...

 

 

In my FSM for 1996 ( I suspect same for other years), it says the CEL comes on after «two consecutive trips with fault». For P0420.

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