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comment by sub tech re: P0420


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Ignorant question: What's this "non-fouler?"

 

Aside: I am aware that it's against federal regs to tamper with or alter emissions-control systems. I don't have any code that I'm trying to correct, and frankly I prefer emission-controlled vehicles. I'm just curious about this.

 

 

 

Credit for the original fix goes to Peaty of Scoobymods.

 

If you have an upgraded or aftermarket exhaust installed, you might get the P0420 CEL since the rear O2 sensor is seeing more flow and thinks something is wrong with the catalytic converter. By installing a rear O2 spacer, you can reduce the amount of flow the rear O2 gets, and stop the CEL.

 

Once again, I am not responsible for anything you do to harm anything or anyone.

 

Tools needed:

-22mm wrench (or 22mm open sided socket w/ breaker bar)

-1/2 inch drill bit

-1/4 inch drill bit (anything in this range will work; you just need to open up the second spacer for more flow)

-Drill (drill press would be way easier)

-Vice

-Jack/jackstands

 

Items/Materials:

-Help! Spark Plug Non-Fouler part # 42002 (#42009 works as well)

-PB blaster (if you can't get the sensor out)

-30 minutes (you'll never get this back)

 

 

found here with pictures

 

http://www.sl-i.net/FORUM/viewtopic.php?f=39&t=14675&start=0

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Credit for the original fix goes to Peaty of Scoobymods.

 

I seriously doubt that. Who knows where it originated, but people have been doing this since shortly after OBD-II came out. I first learned about it while searching for an easy fix for a bad cat code on a Hyundia.

 

It's not a Subaru specific mod and works on many OBD-II vehicles - they all have a #2 O2 sensor to check the efficiency of the cat and they are all subject to cat failure and most of them will respond to this mod.

 

GD

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I seriously doubt that. Who knows where it originated, but people have been doing this since shortly after OBD-II came out. I first learned about it while searching for an easy fix for a bad cat code on a Hyundia.

 

It's not a Subaru specific mod and works on many OBD-II vehicles - they all have a #2 O2 sensor to check the efficiency of the cat and they are all subject to cat failure and most of them will respond to this mod.

 

GD

 

 

its the credit from where the original poster got the write up from fyi

 

 

and the 2nd O2 sensor was installed originally because of so many of us removing the cats on the OBD-I cars from the early 90"s ....any one rember a test pipe ..... lol

jeff

Edited by RAYJAY
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and the 2nd O2 sensor was installed originally because of so many of us removing the cats on the OBD-I cars from the early 90"s ....any one rember a test pipe ..... lol

jeff

 

Well - while that surely did occur, and in my own driveway sits my '91 Turbo (OBD-I) with a 3" stainless, catless, turbo-back system.....

 

I don't think the legislation that created the OBD-II system was entirely because of people removing the cats as the VAST preponderance of cars on the road on completely unmodified. It was merely to make the "self-diagnostic" system more robust and to detect failures which would lead to poor emmissions quality but otherwise go unoticed by the consumer.

 

They aren't after us folks that modify our engines. They are after the 99 other people that don't. Easier target and better returns for the investment by far. If they come after me I'll just find another way around it. If I have to buy two identical cars and pull the freakin dash out each time I hit the emissions place so the VIN matches..... see what I mean? The system (IE "The Man") can't beat us. So why would they try? Answer - they really don't.

 

GD

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its the credit from where the original poster got the write up from fyi

 

 

and the 2nd O2 sensor was installed originally because of so many of us removing the cats on the OBD-I cars from the early 90's ....any one rember a test pipe ..... lol

jeff

 

'90's?... I had test pipes on my V-8 Monza in the 80's. Test/track pipes have been around for a long time. anti-foulers have been around for far longer than that.

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