DIY P0420 fix

[Felipe]

I got a P0420 code and started surfing the net for info and fix, along with my options. I came across this video and was wondering if any one done this?

http://www.youtube.com/watch?v=GqDmmLQ4pG

Im willing to try it... Just need the size for the non fouler or the o2 sensor thread size

[decke48]

18x1.25 mm . The foulers need to be drill to make it work iirc. I bought one of the "p0420 spacers" for $15 awhile back. Could be just the o2 sensor too

[Felipe]

Thanks for the quick info. Ill post up if it works :0)

[Felipe]

so i bought the spacers... drilled one and connecte the other one, but it didnt fit. so i just put in the drilled one (one spacer instead of two) to see if that works. clear the CEL and drove it. 60+ miles later no CEL!!!

[Grimmrican]

Would u be so kind as too where u got the product and what they look like?

[Felipe]

i got thies...exact same ones. got them from pepboys...you can get them at any auto parts store. one set is a lil shorter, i use the shorter ones on my wifes car (still nee to drive it 50+ miles to see if comes back) im sure it wont since i use both.
https://sl-i.net/FORUM/images/imported/2013/04/imagesqtbnANd9GcRKOBlmTwfMXzxNe1V7_GZRuo-1.jpg

heres some difrent ones, but the spacers are the same. 18mm is what i got for my car.
https://sl-i.net/FORUM/images/imported/2013/04/14321d12244800945fix5sparkplugnonfouler-1.jpg
https://sl-i.net/FORUM/images/imported/2013/04/14322d12244805875fixnapa_7302442-1.jpg
https://sl-i.net/FORUM/images/imported/2013/04/imagesqtbnANd9GcTzBLq5k1K6l9DEg6Wl7IXAjY-1.jpg
https://sl-i.net/FORUM/images/imported/2013/04/imagesqtbnANd9GcTzBLq5k1K6l9DEg6Wl7IXAjY-1.jpg
https://sl-i.net/FORUM/images/imported/2013/04/DSC_0068-1.jpg

drill one out like this, not sure on size of drill bit (i think you can skip this if you have the angle ones)
https://sl-i.net/FORUM/images/imported/2013/04/foulers0004-1.jpg
https://sl-i.net/FORUM/images/imported/2013/04/20110223_155428_20110224_085525-1.png
https://sl-i.net/FORUM/images/imported/2013/04/imagesqtbnANd9GcT81QUp1gp69fIzXfFJ0lrMKK-1.jpg

connect the drilled and the non-drilled together and this is your goal.
https://sl-i.net/FORUM/images/imported/2013/04/image011-1.jpg
https://sl-i.net/FORUM/images/imported/2013/04/imagesqtbnANd9GcQli_LNT8IJufgckyOgIqCy6d-1.jpg
https://sl-i.net/FORUM/images/imported/2013/04/page__module__images__section__img_ctrl_-1.jpg
https://sl-i.net/FORUM/images/imported/2013/04/imagesqtbnANd9GcR5I9nVKPaTzIeEQhK3D3EXO1-1.jpg

now just put it back in the bung hole an reset the CEL
https://sl-i.net/FORUM/images/imported/2013/04/attachmentphpattachmentid77039stc1d12597-1.jpg
https://sl-i.net/FORUM/images/imported/2013/04/lotus228-1.jpg
https://sl-i.net/FORUM/images/imported/2013/04/DSC00007JPG-1.jpg

but like i said my faulers did not fit (maybe the shorter ones will) it all depends on your space area... and they not have any angled ones. i just put mine in like this one spacer and is working just fine. (crossing fingers lol)
https://sl-i.net/FORUM/images/imported/2013/04/page__module__images__section__img_ctrl_-2.jpg
https://sl-i.net/FORUM/images/imported/2013/04/imagesqtbnANd9GcRLZULBIesJt2BbQg1aLXT70q-1.jpg
https://sl-i.net/FORUM/images/imported/2013/04/image009-1.jpg

look at the video on the first post if your still stuck on what to do.

[Grimmrican]

Awesome I saw these at work in the help section I figured u were talking about these but I noticed it said spark plug foulers.

[ctbrighton]

now just put it back in the bung hole an reset the CEL
https://sl-i.net/FORUM/images/imported/2013/04/attachmentphpattachmentid77039stc1d12597-1.jpg

VERY important to use TP on the bung hole before this step!

[Felipe]

lmao dont forget to flush

[Grimmrican]

now just put it back in the bung hole an reset the CEL
https://sl-i.net/FORUM/images/imported/2013/04/attachmentphpattachmentid77039stc1d12597-1.jpg

VERY important to use TP on the bung hole before this step!
Haha I see what u did there :D

I am the GREAT CORNHOLIO

[Odycee]

TP?

[Grimmrican]

TP?
Are u serious???? Am I really this old that u don't know what TP is lol it's ok I'll tell ya. It stands for toilet paper. From bevis and butthead. Most likely before it time u young whippersnapper lol

[Odycee]

That's what I thought but to bung the hole?

[Grimmrican]

That's what I thought but to bung the hole?
Not to bung the hole but for the bung hole big difference lol. U need some YouTube my friend research beavis an butthead. I'll love it. Was probably one of the best shows to look forward to on MTV when try only played music. I miss them days

[Felipe]

so i have this 1 extra "space/non fouler" non drilled, but can be drilled and shippe for the right price i guess...

[Odycee]

Any updates P0420 fix? How many miles driven w/no CEL?
Just bought mine, I'd buy them from you if you posted it earlier.

[Felipe]

100+ miles no cel...

[Felipe]

just came back from doing my star smog certifide only (aka test only)... ith the fauler on... you cant even tell its on there, soo yeah it passed.

now i just need to do the civic... same situation with faulers lol

[Odycee]

No change in MPG? Please update again once you get to 200 miles cuz the "Ready Status" might not be set yet.

[Felipe]

Cel code reading cycle is abut 50 - 100 miles after cel has ben reset. I had reset my cel twice before this fauler mod. Both times came back on right on the 50 mile mark. Same goes with the civic, it was about 55 - 60 when i got a cel back on.

[Felipe]

I did this with one fauler... Def will work with both faulers

[Odycee]

I'm installing double fouler this weekend and will update you my result.

Prior to fouler installed, rear O2 sensor must has seen more unburned oxygen meaning engine runs lean?
And with fouler seeing less O2, meaning running correctly or rich?

[Felipe]

Iirc... Sounds about right, I was do for a tune up and had build up on the sensor i guess. Whe i took the sensor out, i tapped it on the floor and buld up came out lol

Did the whole tune up... Now im running under normal levels... And still had cel. so i installed faulers and no cel now

I think the first o2 does the fixing and mixing with air and fuel... Second one just tells you if your cat or sensor is dirty.

[Odycee]

Tried this but found no space for dual spacer, did you have to use 90 degree one?

[Felipe]

Im way passed the 200 mile mark... No cel :0)

No... If you read up a few post.... Theres a section where i noted that both foulers/spacers did not fit. I went along and used only one spacer/fouler (drilled out one) to see if that would work.... And it did!!!

[Odycee]

Installed mine today with ONLY one fouler since 2 didn't fit and will update when I get to 200 miles to make sure all sensors have "Ready Status". Thanks for your update.

Any changes in MPG since it should run leaner now?

[Felipe]

Havent done mpg testing.... I keep forgeting lol

[Odycee]

Within 30 miles cel came back after ecu reset. Damn it.

[Felipe]

Try to get the bent ones or dont drill all the way on the second one. Leave that lilmhole at the end still intact?

[Odycee]

Ok, I'll try again with one w/out drilled hole.

[Felipe]

Drill it but dont drill it all the way... Just enough to screw the sensor in. Try taping it to get some carbon build up out.

[Bhatman]

Installed mine today with ONLY one fouler since 2 didn't fit and will update when I get to 200 miles to make sure all sensors have "Ready Status". Thanks for your update.

Any changes in MPG since it should run leaner now?

Did you put the 02 spacer on the rear sensor or the front? The front sensor is the Air/Fuel sensor which is before the first cat converter. The spacer should technically be installed on the rear 02 sensor which detects the voltage difference as the exhaust flows through the 1st cat.

This older DIY is a bit more detailed: viewtopic.php?f=39&t=14675 (https://sl-i.net/FORUM/viewtopic.php?f=39&t=14675)

[Odycee]

Installed mine today with ONLY one fouler since 2 didn't fit and will update when I get to 200 miles to make sure all sensors have "Ready Status". Thanks for your update.

Any changes in MPG since it should run leaner now?

Did you put the 02 spacer on the rear sensor or the front? The front sensor is the Air/Fuel sensor which is before the first cat converter. The spacer should technically be installed on the rear 02 sensor which detects the voltage difference as the exhaust flows through the 1st cat.

This older DIY is a bit more detailed: viewtopic.php?f=39&t=14675 (https://sl-i.net/FORUM/viewtopic.php?f=39&t=14675)
Installed at rear sensor.

[Bhatman]

Installed mine today with ONLY one fouler since 2 didn't fit and will update when I get to 200 miles to make sure all sensors have "Ready Status". Thanks for your update.

Any changes in MPG since it should run leaner now?

Did you put the 02 spacer on the rear sensor or the front? The front sensor is the Air/Fuel sensor which is before the first cat converter. The spacer should technically be installed on the rear 02 sensor which detects the voltage difference as the exhaust flows through the 1st cat.

This older DIY is a bit more detailed: viewtopic.php?f=39&t=14675 (https://sl-i.net/FORUM/viewtopic.php?f=39&t=14675)
Installed at rear sensor.

If the CEL is going off then at 30 miles and the spacer isnt working...you may either have a exhaust leak or the cat has truthfully gone bad. I had the same problem last year and went through the sequence of:

bad gas --> exhaust check --> ECU reset --> 02 spacer --> cat check

I ended up having a huge crack in my cat...had to get it swapped before smog...no problems since.

[Felipe]

Where was that thread when i needed it? lol

[Odycee]

Crack at the cat flange? Don't see how the cat can crack.

[Felipe]

Maybe the welding? We all know Rust can be a.... lol

[Bhatman]

Crack at the cat flange? Don't see how the cat can crack.

Not at the flange technically, it was inside the cat substrate, and a huge chunk was out too.

[Felipe]

Any updates?

Im still rolling with no cel :0)

[Odycee]

Fouler didn't work, next is to replace CC and will post result.

[Felipe]

That sucks... You never did find an L shaped fauler?

[Odycee]

I don't think L shape would work because I have Torque SW to view my o2 rear sensor real time graph and it oscillating like crazy while it should be a flat line. And p0420 triggered all the time which is worst then original setup.

[Felipe]

Maybe its the sensor?

[Odycee]

Rear sensor is new.

[Felipe]

It should of worked... Even with no cats the faulers should of worked.

[Odycee]

Reinstall original setup cel occurrences less.

[TheGr8Ox]

This didn't work for me, had to replace the converters, and now I'm golden.
Got a good deal on direct replacements from catalyticconvertersonline.com
Just my 2 cents
Unfortunelty for me being in California it's more $$$ but for all you other 49 states, it's much cheaper.

[Odycee]

I just removed my cat, try to clean it with CITRIC ACID as one of the RS25 member had done to clean his cat which works for him. I also have a good used spare to install if old one doesn't work out. However, when I look at the failed cat the honey comb looks perfectly clean and white. Wonder how it failed?

I'll update progress if it works out or not after this weekend. That extended O2 sensor didn't work for me.

http://www.rs25.com/forums/f190/t195805-p0420-fix.html

[Felipe]

Update...

Still have the spacers on.... No cel.

[Felipe]

Something cool I just stumbled upon... regarding p0420
http://m.youtube.com/watch?v=ZlPadYU2mPg

[Odycee]

Rear bung O2 sensor spacer failed, code returned after ECU reset.

After removed cat, pour hot water mixed with citric acid into the cat, sat for 2 days, dumped out blacken carbon residue. Reset ECU and ran up to now WITHOUT P0420 returned, that's about 4 months.
Update: April 2015 - P0420 never returned after cat cleaned with citric acid.

http://www.amazon.com/MILLIARD-100%25-Pure-Grade-Citric/dp/B00EYFKNL8/ref=sr_1_1?ie=UTF8&qid=1429206576&sr=8-1&keywords=citric+acid

Nov 2015 - Still no P0420 to date.