96 legacy 2.2 sedan

my neice took her car in to her mechanic who specializes in subarus

 

she has a cel light that comes on and off

he read it and said it was 420F...and he said it was the catalytic converter

Anyone know if this is correct...if so, what is the code really telling?

thanks in advance

Bill

i had a 420 code and it was the gas cap does it read something about emission control?

420 is normally the cat. subarus tolerances with the o2 readings for this are sooooo tight. just when it will start to read a difference in catalyst efficiency it will throw the light.

maybe it was 440, sorry

yeah p0420 is bad main cat...

P0420 CAT CAT Efficiency Below Threshold

P0440 EVAP EVAP Emission Control System

-=Suberdave=-

www.suberdave.com

The converters are really expensive but the front ox sensors are cheap and easy. A leaking exhaust or a slow front sensor can also cause the cat to go below threshold. An ox sensor is a consumeable like a spark plug and should be replaced at about 90,000 miles but nobody does until they get a code.

I put in a $60 ox sensor that took me about 15 minutes a year ago for a code PO420 and I haven't seen it again. If somebody has done something dumb and damaged the cat of couse this is unlikly to work but should be changed anyway if it is old.

Dumb things that wreck a cat include hitting it in off road use, and any form of neglected maintence that dumps raw gas in it, as well as the ever popular useing of leaded gas.

The converters are really expensive but the front ox sensors are cheap and easy. A leaking exhaust or a slow front sensor can also cause the cat to go below threshold. An ox sensor is a consumeable like a spark plug and should be replaced at about 90,000 miles but nobody does until they get a code.

I put in a $60 ox sensor that took me about 15 minutes a year ago for a code PO420 and I haven't seen it again. If somebody has done something dumb and damaged the cat of couse this is unlikly to work but should be changed anyway if it is old.

Dumb things that wreck a cat include hitting it in off road use, and any form of neglected maintence that dumps raw gas in it, as well as the ever popular useing of leaded gas.

 

Thanks Cookie and others

I'll try the cat.....Funny thing, the expert subaru guy (this guy is very good) did not offer any other solution than saying it was the cat

 

When you say $60 cat...is that a subie cat or an aftermarket?

Thanks Cookie and others

I'll try the cat.....Funny thing, the expert subaru guy (this guy is very good) did not offer any other solution than saying it was the cat

 

When you say $60 cat...is that a subie cat or an aftermarket?

 

he said 60$ o2 sensor. oem is 80$ online. advance auto is 102$.