YellowPro5
Member
when using the non fouler do you need to change out the o2 sensor???? to get it to keep from throwing the code again??
How to cure Cel/Mil from removing cat with Non-Fouler
- Thread starter Rac3rX
- Start date
No. All you need to do is make the non-fouler and attach your existing O2.
I had the same code recently and replaced the plugs and cables as advised by my mechanic and the issue was still there. Then came to find out one of the ignition coils was bad and replaced that and its all good.
I also just installed a new header in my p5 and after about 20 miles the cel was triggered. I'm here finding my solution and will be hooking it up right tomorrow. Will this pass emissions testing? I sure hope so.
I stopped at Salvo when I went for my cruise after finishing up today I heard some clacking coming from the underneath were the header bolts to the main cat and was thinking..damn thats not good! Thanks to RacerX I believe I know the problem. I love you guys!(headbang)
Hello to all my fellow forum members. I have a 2.0L 2001 protege ES manual with 97000 miles on it right now. For the last 3 months or so, I have been throwing a P0421 code every now and then. I assume my pre-cat was going bad. I kinda ignored it. Can't remember the code number, but I have a new code which refers to the 2nd O2 going bad.
Wanted to do the non-fouler trick to get rid of the P0421 code. Questions is will the non-fouler work with a bad O2 sensor? Also, assuming that the O2 wasn't bad, will that eliminate the P0421 code with a bad pre-cat? I ask this because I know most of you who use this trick is because of a header installation... Has anyone used this trick for a bad pre-cat? Thanks for any insight.
Wanted to do the non-fouler trick to get rid of the P0421 code. Questions is will the non-fouler work with a bad O2 sensor? Also, assuming that the O2 wasn't bad, will that eliminate the P0421 code with a bad pre-cat? I ask this because I know most of you who use this trick is because of a header installation... Has anyone used this trick for a bad pre-cat? Thanks for any insight.
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justanothermp5
Banned
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- Rust Bucket
hey does anybody know the recent part number for this? i tried the part number given but it didnt come up as anything, i was at autozone but he was using the parts exchange thing and nothing came up
plus this is over 2 years old,
edit: nevermind looked it up on napas website and its still the same part number, i guess autozone just doesnt have the right stuff
plus this is over 2 years old,
edit: nevermind looked it up on napas website and its still the same part number, i guess autozone just doesnt have the right stuff
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shane02pro5
25ish_psi
- :
- New Caney TX
Yes only on the 2nd
LASERBLUE135
Registered Pimp
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- Laser Blue MSP
I swapped exhaust after 2 years and they were rusted to all hell. But they worked!
whitewaterjava
Member
2.5 Millenium
Wondering if you can help me out with the placement of the non fouler set up on my 2.5 V6 Millenium S. My error code is PO420 - catalyst efficiency below threshold Bank 1. This is a California setup where the pre cat is not attached to the manifold but, is under the floorboard. My understanding is that Bank 1 is closest to the firewall. Do I place the modified O2 sensor in front of the pre cat or behind it? My guess is behind (or maybe it's on the pre cat itself). Please note that my objective is to pass smog (not fun in CA), install a new universal pre cat (high flow if it's appropriate) in its place and save a grand in the process.
Thanks for any help or suggestions you can give me.
Oh, and the reason I'm not taking any chances with the pre cat is that I blew a Ford 351 Cleveland motor in my RV ten years back because of a clogged cat. The CEL didn't come on at all and it ended up costing me over 4 grand. Some people on this thread seem to think that there's an inherent problem with the ECM "falsely indicates an emission concern" I'm not sure I want to take that chance. I'd respect your opinion on this if you have time to reply on this as well.
Thanks again, and if there's a special charity that I can donate $50 in your name, give me that info as well.
Wondering if you can help me out with the placement of the non fouler set up on my 2.5 V6 Millenium S. My error code is PO420 - catalyst efficiency below threshold Bank 1. This is a California setup where the pre cat is not attached to the manifold but, is under the floorboard. My understanding is that Bank 1 is closest to the firewall. Do I place the modified O2 sensor in front of the pre cat or behind it? My guess is behind (or maybe it's on the pre cat itself). Please note that my objective is to pass smog (not fun in CA), install a new universal pre cat (high flow if it's appropriate) in its place and save a grand in the process.
Thanks for any help or suggestions you can give me.
Oh, and the reason I'm not taking any chances with the pre cat is that I blew a Ford 351 Cleveland motor in my RV ten years back because of a clogged cat. The CEL didn't come on at all and it ended up costing me over 4 grand. Some people on this thread seem to think that there's an inherent problem with the ECM "falsely indicates an emission concern" I'm not sure I want to take that chance. I'd respect your opinion on this if you have time to reply on this as well.
Thanks again, and if there's a special charity that I can donate $50 in your name, give me that info as well.
LASERBLUE135
Registered Pimp
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- Laser Blue MSP
(hmm)err, umm, I had the same problem on my Prolege and my Tribune, but my RS-8 never had that problem. What kind of car do you drive?
I apologize in advance
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It sounds like you do have to replace an O2 sensor and it sounds like it is the sensor before your pre cat. I don't understand what you said; do you have a pre cat on your car? I know I had a similar issue in my protege 5 but I did have 2 error codes that came down to needing to replace the pre cat and also had to replace an O2 sensor. If you only have this single code then it sounds like it is just the O2 sensor and if you have a modified system with no pre cat then it may be the sensor after the pre cat location that is causing the code. If you look it up and find that bank 1 is the first O2 sensor in the series then I would replace it and you should be good to go. It doesn't sound like you have any other problems with your car but if you do still have the pre cat hooked up that may be getting dirty and may need to be replaced soon. You will get an error code should that happen and your Mazda has a much better or at least newer engine than that old Ford 351. Back then information about what your car is doing wasn't so available for the driver but these days the cars let you know pretty quickly.
Bluemica3.5
Member
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- 2003.5 mazdaspeed protege (Laser blue Mica) 2002 protege5
im going to have to try this out this week when i get my new exhaust.
LASERBLUE135
Registered Pimp
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- Laser Blue MSP
you can buy these "pre-drilled" or whatever on ebay. They are cheap and I'm sure work just as well.
shane02pro5
25ish_psi
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- New Caney TX
Did you relocate it to after the cat?
