P0420 Catalyst System Efficiency Below Threshold (Bank 1)?! - Subaru WRX Forum
 
LinkBack Thread Tools Display Modes
#1 Old 02-05-2008, 10:48 PM
WRXtuners Member
 
IH8PVMNT's Avatar
 
Join Date: Oct 2007
Location: New York
Posts: 341
Images: 5
IH8PVMNT is an unknown
P0420 Catalyst System Efficiency Below Threshold (Bank 1)?!

so i was cruiseing home yesterday after work at say 40mph local road 2k rpm not beating on it and my check engine poped on i didnt feel any driveablity difrence so i turned back around and went to get my scann tool from work, pulled a p420 for the cats... now i know usually when i get htis code at work on a customer car the cats are known to go bad... o nthe jeeps at least.... but my car is so far completey stock as far as exhuast. all i currently have it a spt intake.... and ironicly have the coob ap and invidia 3 inch catless dp on the way.... any one goten this code before on an all stocker... some thing common??
IH8PVMNT is offline  
Sponsored Links
Advertisement
 
#2 Old 02-06-2008, 06:03 AM
WRXpert
 
dumdum's Avatar
 
Join Date: Sep 2004
Location: Virginia
Posts: 2,800
Images: 12
dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention dumdum is a WRX tech God, pay attention
Has to do with the rear O2 sensor.Maybe the sensor is bad,shorted wire, or unplugged.You car should still be under warrenty right?For the 32 bit ECU cars (All STi's and 06+ WRX) this sensor is kinda important.I would get it fixed soon as ya can.

Homebrewed tuned with Opensource!
dumdum is offline  
#3 Old 02-27-2008, 09:24 PM
WRXtuners Member
 
Join Date: Jan 2006
Location: Massachusetts
Posts: 68
Images: 2
octoparrot is an unknown
Send a message via AIM to octoparrot
Quote:
Originally Posted by dumdum View Post
Has to do with the rear O2 sensor.Maybe the sensor is bad,shorted wire, or unplugged.You car should still be under warrenty right?For the 32 bit ECU cars (All STi's and 06+ WRX) this sensor is kinda important.I would get it fixed soon as ya can.
Isn't this the code for an aftermarket exh (prob catless)? My buds got an 07 and i put a mecanical fix and it was great as soon as we put it on. i got an extra one, brand new for sale... email me if you want it agalambos@caton.com

OCTOPARROT
octoparrot is offline  
#4 Old 02-28-2008, 06:48 AM
WRXtuners Member
 
Longshot's Avatar
 
Join Date: Aug 2007
Location: Connecticut
Posts: 1,119
Images: 5
Longshot is a helpful contributing member
Send a message via AIM to Longshot
Quote:
Originally Posted by octoparrot View Post
Isn't this the code for an aftermarket exh (prob catless)? My buds got an 07 and i put a mecanical fix and it was great as soon as we put it on. i got an extra one, brand new for sale... email me if you want it agalambos@caton.com
The code is for the rear sensor like dumdum said. If you were to switch to an aftermarket DP it may trigger this because of the increased airflow. In this case though, since it's only the stock DP, he's probably correct in saying it's the sensor itself, or the wiring. The OP doesn't need a mechanical fix.

Mike
DTRacing Tuned
Longshot is offline  
#5 Old 02-28-2008, 09:24 AM
WRXtuners Member
 
IH8PVMNT's Avatar
 
Join Date: Oct 2007
Location: New York
Posts: 341
Images: 5
IH8PVMNT is an unknown
i figured it out its nothing to do with the sensors i probed them all checked out ok and what not,.... i jusr recently added that redline fuel system cleaner to my tank... and i think it dumped all of the crap into the cat and destroyed it i clear the code and it comes back every other tank of gas.... ive seen this happen b4 on the jeeps at my dealer... its ok catless dp this weekndf!!!!!!!!!1
IH8PVMNT is offline  
#6 Old 02-28-2008, 12:12 PM
WRXtuners Member
 
Join Date: Jan 2006
Location: Massachusetts
Posts: 68
Images: 2
octoparrot is an unknown
Send a message via AIM to octoparrot
My mistake, didnt see that it was stock dp.

OCTOPARROT
octoparrot is offline  
#7 Old 12-17-2008, 07:18 PM
WRXtuners Member
 
Join Date: Mar 2008
Location: Massachusetts
Posts: 53
Images: 2
413TreX is an unknown
Quote:
Originally Posted by dumdum View Post
Has to do with the rear O2 sensor.Maybe the sensor is bad,shorted wire, or unplugged.You car should still be under warrenty right?For the 32 bit ECU cars (All STi's and 06+ WRX) this sensor is kinda important.I would get it fixed soon as ya can.



would that same code come up if the rear o2 sencer was not in the same position as stock (when installing TXS stealth TBE w/cat accedently put it on pointing to the drivers side) or does it rely on just being plugged in?
413TreX is offline  
#8 Old 12-18-2008, 03:41 PM
WRXtuners Member
 
03 CrazyTaxi's Avatar
 
Join Date: Jan 2006
Location: Missouri
Posts: 728
Images: 4
03 CrazyTaxi is known to be trustworthy and helpful 03 CrazyTaxi is known to be trustworthy and helpful
Send a message via MSN to 03 CrazyTaxi Send a message via Yahoo to 03 CrazyTaxi
Just needs to be plugged in. Is it a high flow cat? That may have something to do with it.

VF34'd Corvette Killer aka Doug
03 CrazyTaxi is offline  
#9 Old 12-18-2008, 06:24 PM
WRXtuners Member
 
Join Date: Mar 2008
Location: Massachusetts
Posts: 53
Images: 2
413TreX is an unknown
yeah its a hiflo cat
413TreX is offline  
#10 Old 12-19-2008, 07:42 PM
WRXtuners Member
 
03 CrazyTaxi's Avatar
 
Join Date: Jan 2006
Location: Missouri
Posts: 728
Images: 4
03 CrazyTaxi is known to be trustworthy and helpful 03 CrazyTaxi is known to be trustworthy and helpful
Send a message via MSN to 03 CrazyTaxi Send a message via Yahoo to 03 CrazyTaxi
I'm not trying to sound like a jerk but were you thinking that a cat is a cat so you wouldn't need a tune?

The increased flow through the aftermarket cat will be noticed by the ECU.

VF34'd Corvette Killer aka Doug
03 CrazyTaxi is offline  
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On