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Yet another P0420 thread

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Here's the story:

 

2001 Forester. 100K miles or so.

 

P0240 code. Still in warranty, used car dealer replaces cat. Code gone.

 

At some point, I replaced the front O2 sensor, (with NAPA / Bosch) I don't rember what code led me there.

 

Time passes.

 

P0420 again.

 

Replace the rear O2 sensor. (with NAPA / Bosch) A couple of early re triggers of P0420, but it stays gone after a few trips.

 

2 year emmissions test due now, so what happens??:mad:

 

Now I am getting the P0420 code again!

 

(I have a scanner, cleared the codes to verify not just a fluke, etc.)

 

Any ideas?

 

If were solely up to me, I'd sell the Forester and get another EA82!

Yes...

 

the front 02 sensor has to be a subaru sensor. The rear can be anything. Non OE has a differnt response time and will throw a code.

 

 

nipper

Also make sure you don't have any exhaust leaks before or shortly after the rear sensor. Even little pinhole leaks.

Yes...

 

the front 02 sensor has to be a subaru sensor. The rear can be anything. Non OE has a differnt response time and will throw a code.

 

 

nipper

the front O2 sensor for subaru is manufactured thru Bosch and the rear one is manufactured thru Denso
the front O2 sensor for subaru is manufactured thru Bosch and the rear one is manufactured thru Denso

 

I worked for an auto part mfg. There is a difference between what you get at the dealership and what you get at the autoparts store. Its sometimes not enough to mean anyhting, but when it comes to emissions it does. The part does meet spec, but the part that comes through subaru has better tolerances.

 

 

nipper

it makes sense what you have to say above but tempting to think otherwise when you are quoted $259 (subaru boxed) for the front O2 and then online get it for $55 (Bosch) ... I hate to pay sometimes 2- 4 times more for the seemly same item just because it falls out of the dealer box...when enough time goes bye even the parts that presently pass thru the dealer will become more inferior..for ex: with my Older subi's or vw's the parts coming from the dealers now don't even come close to the once original

The front o2 sensors for certain years were made by Bosch, but I don't think that's true of all years. I know the OEM Subaru front o2 sensor I ordered for my '94 Legacy did say Bosch on it. That price of $259 for the oem must've been like twice list price; I think I paid about $90 for mine online.

 

One of my local Subaru dealers doubles the list price on walk-in sales. The other charges Subaru list price, but on their invoice they increase the list price by about 20% and then say they gave you a 20% discount off list, which comes out to the msrp price.

The front o2 sensors for certain years were made by Bosch, but I don't think that's true of all years. I know the OEM Subaru front o2 sensor I ordered for my '94 Legacy did say Bosch on it. That price of $259 for the oem must've been like twice list price; I think I paid about $90 for mine online.

 

One of my local Subaru dealers doubles the list price on walk-in sales. The other charges Subaru list price, but on their invoice they increase the list price by about 20% and then say they gave you a 20% discount off list, which comes out to the msrp price.

$259 was just one price I received from a dealer..another quoted $440...they don't call them "stealerships" for nothing
Here's the story:

 

2001 Forester. 100K miles or so.

 

P0240 code. Still in warranty, used car dealer replaces cat. Code gone.

 

At some point, I replaced the front O2 sensor, (with NAPA / Bosch) I don't rember what code led me there.

 

Time passes.

 

P0420 again.

 

Replace the rear O2 sensor. (with NAPA / Bosch) A couple of early re triggers of P0420, but it stays gone after a few trips.

 

2 year emmissions test due now, so what happens??:mad:

 

Now I am getting the P0420 code again!

 

(I have a scanner, cleared the codes to verify not just a fluke, etc.)

 

Any ideas?

 

If were solely up to me, I'd sell the Forester and get another EA82!

 

 

 

Engine coolant temperture and/or MAF sensor(s)?

$259 was just one price I received from a dealer..another quoted $440...they don't call them "stealerships" for nothing

 

Try the online subaru parts houses. The will give you a better price.

 

nipper

  • Author

Ok, I'll get an oem - I found an online Subaru dealer w/ good prices when I did the timing belt stuff. If nothing else, I'll have a spare front O2 sensor.

 

I haven't checked the others, as I only got the 1 code. Good point.

 

When I scanned it (and started this thread) I cleared the memory. The CEL has not come back on yet. I read that some codes take a coulple of cycles to light the CEL.

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