Solutions for eliminating P0420 with AMS O2 spacer on?
#18
Newbie
Thread Starter
iTrader: (2)
Join Date: Jan 2009
Location: Lawrence, KS
Posts: 58
Likes: 0
Received 0 Likes
on
0 Posts
The CEL light will pop out spontaneously, it is not on now does not mean it wont pop out in the future. The best solution is keep AP in your car or get a tune. But the funny thing is after I post the OP, it does not pop out ever since.
#19
Evolved Member
iTrader: (7)
I've had a 0420 code since the day I installed my AMS HFC, about 7-8 months ago, and I'm using their CEL fix. I'm really hoping to find a solution soon so when something actually goes wrong and triggers the CEL, I'll know. My AMS spacer is on the lowest ring due to clearance issues so I'm thinking of trying the Touge Factory one with the bend in it; I'm not sure if that will help.
#20
Evolving Member
Join Date: Jul 2008
Location: Calgary, Alberta, Canada
Posts: 250
Likes: 0
Received 0 Likes
on
0 Posts
I just put in my T1R 90R catback with the resonated test pipe and got this CEL. Hope there is a fix soon. I've read a few posts on here and seems like a tune can fix thiis issue? I'm kinda confused by this, how would a tune fix it?
#21
Evolved Member
iTrader: (12)
Join Date: Jan 2009
Location: Massachusetts
Posts: 552
Likes: 0
Received 0 Likes
on
0 Posts
I've had a 0420 code since the day I installed my AMS HFC, about 7-8 months ago, and I'm using their CEL fix. I'm really hoping to find a solution soon so when something actually goes wrong and triggers the CEL, I'll know. My AMS spacer is on the lowest ring due to clearance issues so I'm thinking of trying the Touge Factory one with the bend in it; I'm not sure if that will help.
#22
Evolved Member
iTrader: (9)
So what is the final software fix combo that works for USDM 5 speed cars?
I was fine with the angled design UR Mini-Muffler test pipe for 2 years then this spring I would once every month get a CEL light indicating the P0420 Catalyst Efficiency Below Threshold. It seemed that if I drove the car more conservatively and cruised at lower RPM's it would have a higher chance to trigger. I also noticed once that it reported voltage being low on the rear O2 sensor location but I only saw that once.
Fast forward to the last week and my inspection is due... Well now the bloody P0420 code is being relentless and the third drive cycle is flashing that CEL like clockwork. I added in a spacer last night after cleaning up the sensor a bit with intake cleaner since it appeared a bit clogged up, still got a CEL today. I'm wondering if the sensor isn't seeing enough exhaust flow and the UR mini-muffler hole is clogged or partially blocked? When I sprayed some intake cleaner in there I could hear it trickle down into the exhaust but I remember that the hole was tiny when I last checked it. Perhaps I need to open up it up slightly and see what happens, then again if I can flash a few bits on ECUflash that would be MUCH more convenient then ripping all that apart for no good reason.
I've done searches and for whatever reason I can't find the final combo of fixes to prevent the P0420 CEL, just back and forth theories on why one car might get fixed while others don't.
I was fine with the angled design UR Mini-Muffler test pipe for 2 years then this spring I would once every month get a CEL light indicating the P0420 Catalyst Efficiency Below Threshold. It seemed that if I drove the car more conservatively and cruised at lower RPM's it would have a higher chance to trigger. I also noticed once that it reported voltage being low on the rear O2 sensor location but I only saw that once.
Fast forward to the last week and my inspection is due... Well now the bloody P0420 code is being relentless and the third drive cycle is flashing that CEL like clockwork. I added in a spacer last night after cleaning up the sensor a bit with intake cleaner since it appeared a bit clogged up, still got a CEL today. I'm wondering if the sensor isn't seeing enough exhaust flow and the UR mini-muffler hole is clogged or partially blocked? When I sprayed some intake cleaner in there I could hear it trickle down into the exhaust but I remember that the hole was tiny when I last checked it. Perhaps I need to open up it up slightly and see what happens, then again if I can flash a few bits on ECUflash that would be MUCH more convenient then ripping all that apart for no good reason.
I've done searches and for whatever reason I can't find the final combo of fixes to prevent the P0420 CEL, just back and forth theories on why one car might get fixed while others don't.
#23
Evolved Member
iTrader: (9)
Likely I should be bumping one of the threads in the tuning section, but it's hard to believe that nobody has found a combo that works in the last 6 months?!?
I was going to just disable the rear O2 by setting "Options 2, Bit1" from 1 down to 0 but for whatever reason it doesn't want to take "0" or "0x0" as a value and remains as 1... Oddly if I type a bunch of jibberish it changes to "0" but then claims the other values just above it changed even though they didn't. This is the latest ECUFlash as far as I know, really strange behavior here.
Update: Used the + and - key and it would toggle the bit back and forth. Still it was indicating that other bits had changed above it even thought hey hadn't, I'll test if it works today.
I was going to just disable the rear O2 by setting "Options 2, Bit1" from 1 down to 0 but for whatever reason it doesn't want to take "0" or "0x0" as a value and remains as 1... Oddly if I type a bunch of jibberish it changes to "0" but then claims the other values just above it changed even though they didn't. This is the latest ECUFlash as far as I know, really strange behavior here.
Update: Used the + and - key and it would toggle the bit back and forth. Still it was indicating that other bits had changed above it even thought hey hadn't, I'll test if it works today.
Last edited by Hiboost; Oct 8, 2010 at 07:01 AM.
#24
Evolved Member
iTrader: (9)
Likely I should be bumping one of the threads in the tuning section, but it's hard to believe that nobody has found a combo that works in the last 6 months?!?
I was going to just disable the rear O2 by setting "Options 2, Bit1" from 1 down to 0 but for whatever reason it doesn't want to take "0" or "0x0" as a value and remains as 1... Oddly if I type a bunch of jibberish it changes to "0" but then claims the other values just above it changed even though they didn't. This is the latest ECUFlash as far as I know, really strange behavior here.
Update: Used the + and - key and it would toggle the bit back and forth. Still it was indicating that other bits had changed above it even thought hey hadn't, I'll test if it works today.
I was going to just disable the rear O2 by setting "Options 2, Bit1" from 1 down to 0 but for whatever reason it doesn't want to take "0" or "0x0" as a value and remains as 1... Oddly if I type a bunch of jibberish it changes to "0" but then claims the other values just above it changed even though they didn't. This is the latest ECUFlash as far as I know, really strange behavior here.
Update: Used the + and - key and it would toggle the bit back and forth. Still it was indicating that other bits had changed above it even thought hey hadn't, I'll test if it works today.
#28
EvoM Guru
iTrader: (6)
Likely I should be bumping one of the threads in the tuning section, but it's hard to believe that nobody has found a combo that works in the last 6 months?!?
I was going to just disable the rear O2 by setting "Options 2, Bit1" from 1 down to 0 but for whatever reason it doesn't want to take "0" or "0x0" as a value and remains as 1... Oddly if I type a bunch of jibberish it changes to "0" but then claims the other values just above it changed even though they didn't. This is the latest ECUFlash as far as I know, really strange behavior here.
Update: Used the + and - key and it would toggle the bit back and forth. Still it was indicating that other bits had changed above it even thought hey hadn't, I'll test if it works today.
I was going to just disable the rear O2 by setting "Options 2, Bit1" from 1 down to 0 but for whatever reason it doesn't want to take "0" or "0x0" as a value and remains as 1... Oddly if I type a bunch of jibberish it changes to "0" but then claims the other values just above it changed even though they didn't. This is the latest ECUFlash as far as I know, really strange behavior here.
Update: Used the + and - key and it would toggle the bit back and forth. Still it was indicating that other bits had changed above it even thought hey hadn't, I'll test if it works today.
1) P0420 = bit flip for ECU_OPTIONS_2
2) P139 and P0140 are in my DTC disable thread
P0140 is new and ive only just fixed it (well a month ago now)
Thread
Thread Starter
Forum
Replies
Last Post
wluc12
09+ Lancer Ralliart General
6
Apr 2, 2017 11:22 AM
Dawid5surowiec
Evo Engine / Turbo / Drivetrain
3
Aug 2, 2013 06:31 PM