Have a 02 Forester L, 150,000 miles, Auto.
Okay...
Have a 0420 code (catalyst system below threshold), in the process of resolving this problem. Tailpipe tip was sooty, my mileage took a dive, & throttle body had tons of carbon built-up. So I figured it might just be the front O2 (A/F) sensor. Cleaned throttle body, replaced fuel filter, plugs & front O2 with a Subaru OEM sensor, 0420 code gone for about 200 miles.
During the time the 0420 code was gone my code reader still gave an incomplete (Inc) monitor analysis of 02 sensor and complete (ready) analysis of; catalyst, O2 heater, misfire, fuel, comp….have known evap problem so this was Inc also. Anyhow after 0420 code returned the list of Inc is; O2 sensor, catalyst and evap. Is it possible the new O2 (A/F) sensor I installed is bad or more likely that is it truly my cat? Going to try the mechanical fix (18mm non-fouler) on rear O2 sensor in a few days to see what happens.
When I was replacing the O2 sensor I noticed coolant on the driver’s side on the steering gear boot. Suspecting the fabled head gasket leak; added the Subaru coolant conditioner yesterday (oil and coolant apperance is nomal, not milky, etc.) If it is a leak just caught it as my level only recently went down by about 1 cup since last I checked a month ago. Oil is also down maybe a 1/5 of a quart in the past 1000 miles which is a first. I remember reading somewhere that a bad head gasket can contribute to shorting the lifespan of your cat. converter as silicone in the coolant can get into the cat and wreak havoc. Anyone have any info on that….? Afraid to install new catalytic converter before I can fix coolant leak.
Okay...
Have a 0420 code (catalyst system below threshold), in the process of resolving this problem. Tailpipe tip was sooty, my mileage took a dive, & throttle body had tons of carbon built-up. So I figured it might just be the front O2 (A/F) sensor. Cleaned throttle body, replaced fuel filter, plugs & front O2 with a Subaru OEM sensor, 0420 code gone for about 200 miles.
During the time the 0420 code was gone my code reader still gave an incomplete (Inc) monitor analysis of 02 sensor and complete (ready) analysis of; catalyst, O2 heater, misfire, fuel, comp….have known evap problem so this was Inc also. Anyhow after 0420 code returned the list of Inc is; O2 sensor, catalyst and evap. Is it possible the new O2 (A/F) sensor I installed is bad or more likely that is it truly my cat? Going to try the mechanical fix (18mm non-fouler) on rear O2 sensor in a few days to see what happens.
When I was replacing the O2 sensor I noticed coolant on the driver’s side on the steering gear boot. Suspecting the fabled head gasket leak; added the Subaru coolant conditioner yesterday (oil and coolant apperance is nomal, not milky, etc.) If it is a leak just caught it as my level only recently went down by about 1 cup since last I checked a month ago. Oil is also down maybe a 1/5 of a quart in the past 1000 miles which is a first. I remember reading somewhere that a bad head gasket can contribute to shorting the lifespan of your cat. converter as silicone in the coolant can get into the cat and wreak havoc. Anyone have any info on that….? Afraid to install new catalytic converter before I can fix coolant leak.
