evolutionm.net - Home of the Lancer Evolution
Home Features Community Marketplace Registry Garage Store

Go Back   evolutionm.net > Lancer Forums > Lancer (ES, LS, OZ) 2002-2007 Forums > Lancer (ES, LS, OZ) Tech Forums > Lancer Troubleshooting
Sign in using an external account
Register Forgot Password?
Search


Lancer Troubleshooting Get help with any troubleshooting problems you may have.

Welcome to EvolutionM.net!
Welcome to EvolutionM.net.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!


Reply
 
 
 
 
Thread Tools Search this Thread
Old Dec 1, 2007, 07:53 PM   #1
Evolved Member
Personal Sales Rating: (10)
Garage is empty, add now
 
SLVROZ_03's Avatar
 
Join Date: Mar 2005
Location: Greenville, SC
Posts: 4,796

Drives: '03 OZ Rally

PO421:Warm Up Catalyst-below threshold (bank #1) CEL

So I searched and came up with only 2 threads with the mention of the PO421...honestly surprised!

What's interesting is that in both the threads both owners had an aftermarket header, so the reason for their CEL would be obvious (no 1st cat). But minus my Greddy EvoII canister, my exhaust system is stock.

Assuming bank #1 meant the first O2 sensor, does "below threshold" mean that the sensor isn't (all of a sudden) getting proper readings from the ecu? or proper readings from the exhaust gases (bad O2)?

I've not done anything to the car lately, and the CEL showed up while cruising down the road...nothing out of the ordinary. Guessing "Stewart" didn't like the fact the wife and I were test driving other cars today!

I had also read that a 2nd generation Eclipse O2 sensor is a direct match to ours? If I remember from the post, it was Alchemist that said that...so I can believe there's truth behind it. But has anyone ever used one?
*Edited for correction and quote :
Quote:
Originally Posted by WADADLIG_OZ View Post
I researched the Mirage forums and found that we share O2 sensors with a 1998 Eclipse turbo 2wd.

I have mine here that I need to install but when I checked it with looking at the one in the car it seems to be the same.

WADAD
Thanks ahead of time for your help and assistance!
__________________
Mission accomplished! Got the garage, and now it's time to play!!!

Last edited by SLVROZ_03; Dec 1, 2007 at 07:58 PM.
Offline
 
Reply With Quote
Old Dec 1, 2007, 09:30 PM   #2
Evolving Member
Personal Sales Rating: (43)
Garage is empty, add now
 
KcEvil8's Avatar
 
Join Date: Jan 2006
Location: chi-town
Posts: 112

Drives: 2008 Mitsubishi Evolution X

Send a message via AIM to KcEvil8
your cat is bad. the ECU look at the O2 sensor before and after the cat to determine the efficiency of the cat. if the 2 O2 sensors data is very close for certain amount of time, the ECU will kick on the check engine light. that why people that have aftermarket exhaust manifold will have the code cause i think the cat is part of the exhaust manifold. bank 1 mean the bank of cylinders where the number 1 cylinder is and 4 cylinders car only have one bank.
__________________
ETS 3.5" MAF Housing...SR*S Catback Exhaust...ichiba test pipe...FP JB Red Turbo...Tomie Poncam...Tomie Widemouth Downpipe...TurboXS 3.5" Intercooler and UICP and LICP
Offline
 
Reply With Quote
Old Dec 2, 2007, 01:35 PM   #3
Evolved Member
Personal Sales Rating: (19)
2002 Mitsubishi Lancer
 
02-Lancer-Es's Avatar
 
Join Date: Aug 2006
Location: San Antonio
Posts: 2,384

Drives: Turbo Lancer Es

dam i just got this code yesterday too!!
__________________
Quickest known automatic Lancer
Stock motor !
12.75 @ 107 mph

256whp 262tq 13psi JMS E85 tune
Offline
 
Reply With Quote
Old Dec 2, 2007, 05:47 PM   #4
Evolved Member
Personal Sales Rating: (10)
Garage is empty, add now
 
SLVROZ_03's Avatar
 
Join Date: Mar 2005
Location: Greenville, SC
Posts: 4,796

Drives: '03 OZ Rally

Were you out test driving other cars too? LOL I think "Stewart" overheard us and decided to be nasty.
__________________
Mission accomplished! Got the garage, and now it's time to play!!!
Offline
 
Reply With Quote
Old Dec 2, 2007, 06:23 PM   #5
Evolved Member
Personal Sales Rating: (19)
2002 Mitsubishi Lancer
 
02-Lancer-Es's Avatar
 
Join Date: Aug 2006
Location: San Antonio
Posts: 2,384

Drives: Turbo Lancer Es

lol nope im only 18 (just turned) and still go to HS so i dont have the cash
but ill prob just fix it
if its the converter its only 130 for one on ebay (obx high flow,bolt on)
but i hope i fixed it by doing a couple things earlier
__________________
Quickest known automatic Lancer
Stock motor !
12.75 @ 107 mph

256whp 262tq 13psi JMS E85 tune
Offline
 
Reply With Quote
Old Dec 2, 2007, 07:17 PM   #6
Newbie
Personal Sales Rating: (4)
Garage is empty, add now
 
Redlancer's Avatar
 
Join Date: Sep 2003
Location: Quebec, Canada
Posts: 88

Drives: 2003 Lancer ES Red

Smile

Quote:
Originally Posted by SLVROZ_03 View Post
So I searched and came up with only 2 threads with the mention of the PO421...honestly surprised!

What's interesting is that in both the threads both owners had an aftermarket header, so the reason for their CEL would be obvious (no 1st cat). But minus my Greddy EvoII canister, my exhaust system is stock.

Assuming bank #1 meant the first O2 sensor, does "below threshold" mean that the sensor isn't (all of a sudden) getting proper readings from the ecu? or proper readings from the exhaust gases (bad O2)?

I've not done anything to the car lately, and the CEL showed up while cruising down the road...nothing out of the ordinary. Guessing "Stewart" didn't like the fact the wife and I were test driving other cars today!

I had also read that a 2nd generation Eclipse O2 sensor is a direct match to ours? If I remember from the post, it was Alchemist that said that...so I can believe there's truth behind it. But has anyone ever used one?
*Edited for correction and quote :

Thanks ahead of time for your help and assistance!
How many miles you got on your car? I change my second 02 at 80 000 miles... A O2 sensors worn out with the time and milage, I'll change the sensors before the cat. (That work good on my car...)

A good read about Oxygen sensors...

http://www.ngksparkplugs.com/tech_su...x.asp?mode=nml
__________________
Progress Sway Bar + Sway bar perches
Ralliart complete suspension
R1 Drilled Sloted Rotor
Kevlar Brake Pad
ASA EM9 17" wheel
UDP Pulley
TWM Short Shifter + Classic knob
Magnecor Spark plug wire
Deyeme Firm Motor Mount
JDM Cedia Ralli///Art Front Grill
RMR SRI

Custom made:
Front & Rear K-BAR
Ported Intake Manifolt
Oversize fuel Rail
Ecuflash custom tune.
Offline
 
Reply With Quote
Old Dec 3, 2007, 01:19 PM   #7
Evolved Member
Personal Sales Rating: (10)
Garage is empty, add now
 
SLVROZ_03's Avatar
 
Join Date: Mar 2005
Location: Greenville, SC
Posts: 4,796

Drives: '03 OZ Rally

I've got 85k miles, so I know an O2 replacement was coming up on the things-to-do list...but it's always at the most inconvenient times!
__________________
Mission accomplished! Got the garage, and now it's time to play!!!
Offline
 
Reply With Quote
Old Dec 3, 2007, 04:22 PM   #8
Newbie
Personal Sales Rating: (4)
Garage is empty, add now
 
Redlancer's Avatar
 
Join Date: Sep 2003
Location: Quebec, Canada
Posts: 88

Drives: 2003 Lancer ES Red

I bougth mine from this compagnie:

http://www.automedicsupply.com/

Good pprice and fast shipping. They work great too.

(Don't buy the universal one... They don't come with the plug.)
__________________
Progress Sway Bar + Sway bar perches
Ralliart complete suspension
R1 Drilled Sloted Rotor
Kevlar Brake Pad
ASA EM9 17" wheel
UDP Pulley
TWM Short Shifter + Classic knob
Magnecor Spark plug wire
Deyeme Firm Motor Mount
JDM Cedia Ralli///Art Front Grill
RMR SRI

Custom made:
Front & Rear K-BAR
Ported Intake Manifolt
Oversize fuel Rail
Ecuflash custom tune.

Last edited by Redlancer; Dec 3, 2007 at 04:25 PM.
Offline
 
Reply With Quote
Old Dec 3, 2007, 04:26 PM   #9
Evolved Member
Personal Sales Rating: (9)
Garage is empty, add now
 
atilla's Avatar
 
Join Date: Jun 2006
Location: NH
Posts: 1,242

Drives: 02 OZ

Send a message via AIM to atilla Send a message via MSN to atilla
if you are using the stock header and you don't have a lot of cash i have my stock header with a working cat that i could send your way for a few bucks.

alternatively you can do the non-fouler trick on the 2nd O2 sensor for maybe five bucks and fifteen minutes of your time and that CEL will disappear.
__________________
my lancer!

RRM / R.I.P. Gabe
Offline
 
Reply With Quote
Old Dec 3, 2007, 04:38 PM   #10
Newbie
Personal Sales Rating: (4)
Garage is empty, add now
 
Redlancer's Avatar
 
Join Date: Sep 2003
Location: Quebec, Canada
Posts: 88

Drives: 2003 Lancer ES Red

Quote:
Originally Posted by atilla View Post
if you are using the stock header and you don't have a lot of cash i have my stock header with a working cat that i could send your way for a few bucks.

alternatively you can do the non-fouler trick on the 2nd O2 sensor for maybe five bucks and fifteen minutes of your time and that CEL will disappear.
If the second O2 sensors is dead, the trick of the non-fouler will not work.

At 85 000 miles, I'm sure the O2 sensors is dead. (Like I have on my car.... Everything was fine and one day, bang the cel for the P0421.)
__________________
Progress Sway Bar + Sway bar perches
Ralliart complete suspension
R1 Drilled Sloted Rotor
Kevlar Brake Pad
ASA EM9 17" wheel
UDP Pulley
TWM Short Shifter + Classic knob
Magnecor Spark plug wire
Deyeme Firm Motor Mount
JDM Cedia Ralli///Art Front Grill
RMR SRI

Custom made:
Front & Rear K-BAR
Ported Intake Manifolt
Oversize fuel Rail
Ecuflash custom tune.
Offline
 
Reply With Quote
Old Dec 3, 2007, 04:40 PM   #11
Evolved Member
Personal Sales Rating: (10)
Garage is empty, add now
 
SLVROZ_03's Avatar
 
Join Date: Mar 2005
Location: Greenville, SC
Posts: 4,796

Drives: '03 OZ Rally

So with it saying bank #1, doesn't that mean the first O2 sensor though?
__________________
Mission accomplished! Got the garage, and now it's time to play!!!
Offline
 
Reply With Quote
Old Dec 3, 2007, 04:55 PM   #12
Evolved Member
Personal Sales Rating: (19)
2002 Mitsubishi Lancer
 
02-Lancer-Es's Avatar
 
Join Date: Aug 2006
Location: San Antonio
Posts: 2,384

Drives: Turbo Lancer Es

i got my code cleared 2 days ago and it hasnt came back!!
i think it was because my spark plug wire was really loose!
__________________
Quickest known automatic Lancer
Stock motor !
12.75 @ 107 mph

256whp 262tq 13psi JMS E85 tune
Offline
 
Reply With Quote
Old Dec 3, 2007, 05:32 PM   #13
Evolved Member
Personal Sales Rating: (10)
Garage is empty, add now
 
SLVROZ_03's Avatar
 
Join Date: Mar 2005
Location: Greenville, SC
Posts: 4,796

Drives: '03 OZ Rally

How'd you clear it? Disconnect the battery?
__________________
Mission accomplished! Got the garage, and now it's time to play!!!
Offline
 
Reply With Quote
Old Dec 3, 2007, 05:34 PM   #14
Evolved Member
Personal Sales Rating: (19)
2002 Mitsubishi Lancer
 
02-Lancer-Es's Avatar
 
Join Date: Aug 2006
Location: San Antonio
Posts: 2,384

Drives: Turbo Lancer Es

nope when u take it to autozone they clear it if u ask them without resetting everything (stereo ,clock)
or you can also reset it by disconnecting the battery for 5 mins!
__________________
Quickest known automatic Lancer
Stock motor !
12.75 @ 107 mph

256whp 262tq 13psi JMS E85 tune
Offline
 
Reply With Quote
Old Dec 4, 2007, 12:09 PM   #15
Evolved Member
Personal Sales Rating: (10)
Garage is empty, add now
 
SLVROZ_03's Avatar
 
Join Date: Mar 2005
Location: Greenville, SC
Posts: 4,796

Drives: '03 OZ Rally

Well dang! The guy never asked while I was there...and it wasn't like they're busy either. I was their only customer! LOL I probably end up disconnecting the battery anyways...it has been a while and fuel has been dipping a little low lately.

Thx
__________________
Mission accomplished! Got the garage, and now it's time to play!!!
Offline
 
Reply With Quote
Old Dec 4, 2007, 12:09 PM
EvolutionM
Mitsubishi Lancer




Paid Advertisement
 
 
 
Reply

Tags
01, bank, cat, catalyst, catalytic, check, converter, efficiency, engine, lancer, light, mitsubishi, p0421, po421, threshold, warm, warming, warmup

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


 









All times are GMT -7. The time now is 07:37 AM.


Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
All Passwords