Looking to do a 02 De fouler this weekend on sensor 2 in my 2006 Toyota Corolla! The question I have is some of the threads I read said drill the De fouler all the way through with a 1/2 bit and other say drill most of it out and leave the original small hole in the end of the Dorman #42009! What is the right way and is there a better benefit of one way over the other?:blink:
O2 Sensor Defouler Question?
- Thread starter MRFIXITUP
- Start date
De-fouling an O2 sensor sounds bogus. These are incredibly sensitive instruments and tampering them by drilling bigger holes can leave you running lean since that will trick the sensor into reading higher than normal oxygen levels in your exhaust.
Just buy a new one. You should every 60,000 miles anyway and they are easy to replace and the fuel savings will pay for the cost of the sensor.
Now, if by the #2 sensor you are referring to the downstream sensor, leave it alone. All the downstream O2 sensor does is measure catalytic converter efficiency, and does not affect your air/fuel ratio at all (the upstream sensor does that). I don't touch the downstream sensor until it fails, but the upstream sensor needs to be maintained for optimum power and mileage.
Just buy a new one. You should every 60,000 miles anyway and they are easy to replace and the fuel savings will pay for the cost of the sensor.
Now, if by the #2 sensor you are referring to the downstream sensor, leave it alone. All the downstream O2 sensor does is measure catalytic converter efficiency, and does not affect your air/fuel ratio at all (the upstream sensor does that). I don't touch the downstream sensor until it fails, but the upstream sensor needs to be maintained for optimum power and mileage.
Guys are you really that uneducated about the defouler? You can buy and add a defouler onto the O2 sensor? You don't drill the O2 sensor!!!!!!!!!:thumbdown: You drill out the defouler. Do a little research, you will find multiple threads of using a spark plug defouler to add onto the O2 sensor to remove the P0420 code for a check engine light. The question is do you drill it out all the way or leave the tiny hole in the bottom of the defouler!
Guys are you really that uneducated about the defouler? You can buy and add a defouler onto the O2 sensor? You don't drill the O2 sensor!!!!!!!!!:thumbdown: You drill out the defouler. Do a little research, you will find multiple threads of using a spark plug defouler to add onto the O2 sensor to remove the P0420 code for a check engine light. The question is do you drill it out all the way or leave the tiny hole in the bottom of the defouler!
You're using it to eliminate a catalyst efficiency below threshold code. That is illegal. If any shop was found to be doing that they would be fined severely and shut down.
Fix the car properly, don't rig it. That's my advice.
Not sure why the OP is bypassing this but it isn't always as easy as you say. At least in my case we replaced the cat and all was well for a few thousand miles...then the CEL came on. Sensor was tested as well as cat...all was fine. We even had to go for a state sniff test and it passed. The only problem was the intermittent CEL. Since the post cat isn't used for fuel trim and all else was well we had to find another solution. From researching this it seems some aftermarket cats have different flow profiles and or sensor locations which throw off the readings. So while I tend to agree you shouldn't just fake out the sensor I do think there are some times you don't have much of a choice.
It takes patience to diagnose, and it does suck at times, but that is owning a car full of technology.
If you look at the signal for an upstream sensor, it constantly changes up and down. If you look at the signal for a downstream sensor, it is relatively flat. The code trips when the downstream signal begins to match the upstream sensor signal. If the catalytic converter was changed to an aftermarket one, it is possible that the aftermarket catalytic converter can't keep up with the exhaust flow of the engine and clean up effectively enough to keep the code from being thrown.
When it comes to exhaust, I try to stick with OEM unless the aftermarket one has been proven to work with the car it is installed on.
If you look at the signal for an upstream sensor, it constantly changes up and down. If you look at the signal for a downstream sensor, it is relatively flat. The code trips when the downstream signal begins to match the upstream sensor signal. If the catalytic converter was changed to an aftermarket one, it is possible that the aftermarket catalytic converter can't keep up with the exhaust flow of the engine and clean up effectively enough to keep the code from being thrown.
When it comes to exhaust, I try to stick with OEM unless the aftermarket one has been proven to work with the car it is installed on.
So called "True Mechanics" have chased the problem before which cost a lot of MONEY! Replace the cat converter, replace the O2 sensor, Replace intake Gasket, replace all of exhaust pipe, replace intake gasket; hell with chasing the problem~~~:thumbdown: As stated, the O2 sensor at the cat only checks BS ratios and does not change them! I have already had certified Toyota mechanics tell me the threshold was too high from the factory. They even talked about a recall, but said it would be too costly to flash every ecm! This is a simple fix and does not "rig" anything! Its a solution to a problem that the manufacture will not fix Mr, "True Mechanic"! Thanks for the feedback about the Audi! Proof is in the pudding or in this case, the defouler~!:thumbsup:
Here is one of the links. This one shows using both defoulers together.
http://www.regalgs.org/topic/50859-...-flow-cat-spark-plug-fouler-trick-w-pictures/
http://www.regalgs.org/topic/50859-...-flow-cat-spark-plug-fouler-trick-w-pictures/
Those aren't true mechanics if they are replacing parts until they find the problem.
Those are pray-and-spray mechanics.
From the link you posted:
"This happens because the High flow cat is letting too much exhaust through without filtering it enough for OEM specs"
Exactly, the catalytic converter he put on was barely doing the job and after a mere 8 months of use it dipped below threshold. Meaning that it isn't doing the job it is designed to do. I've heard about Downstream O2 cheaters for people that remove the catalytic converter all together (which is similar to this).
It's one thing to do this on a race car that is a track queen. It's another thing to do this on a car that is driven daily. The catalytic converter also helps keep back-pressure in the exhaust system, which allows exhaust gases to scavenge out of the combustion chambers more efficiently.
Those are pray-and-spray mechanics.
From the link you posted:
"This happens because the High flow cat is letting too much exhaust through without filtering it enough for OEM specs"
Exactly, the catalytic converter he put on was barely doing the job and after a mere 8 months of use it dipped below threshold. Meaning that it isn't doing the job it is designed to do. I've heard about Downstream O2 cheaters for people that remove the catalytic converter all together (which is similar to this).
It's one thing to do this on a race car that is a track queen. It's another thing to do this on a car that is driven daily. The catalytic converter also helps keep back-pressure in the exhaust system, which allows exhaust gases to scavenge out of the combustion chambers more efficiently.
Well its been a productive day! Rotors turned, new break pads, Installed spark plug defouler, and got rid of that annoying SB alarm! I did the two piece defouler like in this thread video. Worked great, CEL went off and no exhaust leak! Thanks for all the help and feedback! Beats paying my so called mechanic to replace: all of exhaust, New CAT, New O2 sensors! And saved me $845 since the defouler was only 5 bucks! I don't know who discovered this fix, but your a genius in my book! Thanks again!
