o2 sensor defouler/fooler

[Austin-591500]

hey all. recently had to reluctantly pull my cat out because my plenum was that bad. after the straight pipe and plenum redo, the truck runs FAR better. however ive been informed that i need to put a fooler otherwise called a spark plug defouler on the pre-cat o2 in order to not have a bad air-fuel mixture. does anyoe know what size i should get or are they universal? 2001 1500 sport with a 5.9.

 

[PoMansRam]

Anti-foulers do not go on the pre-cat sensor, they go after the catalytic converter and their sole purpose is to attempt to keep catalyst inefficiency codes away. They've got nothing to do with fuel trims.

 

[Dan98]

18 mm but they dont work and down stream sensor will make it run limp if they are bad but no converter will not throw a code it just adjusts trim to confiscate.

Sent from my SM-J260A using Tapatalk

 

[dapepper9]

18 mm but they dont work and down stream sensor will make it run limp if they are bad but no converter will not throw a code it just adjusts trim to confiscate.

Sent from my SM-J260A using Tapatalk

This is not accurate. Downstream sensor only has very minute input in long-term trims, its primary function is monitoring converter efficiency. The use of a spark plug non-fouler messes with the reading the downstream sees and makes it think the converter (or lack thereof) is operating within desirable efficiency limits. The vehicle's automatic trim adjustments are also pretty limited and it's not enough to keep an efficiency code away when a cat is not present. That code will almost always pop up. The non-fouler is used to keep the code away.

The correct answer OP: replace the cat and DO NOT put a non-fouler in the upstream ****

 

[pacofortacos]

If you absolutely do not want a cat, get the big daddy O2 simulator for the downstream O2 sensor.
It will take care of any code issues.
The cheap antifoulers only last a very short time, the big daddy part will last.

http://bigdaddiesgarage.com/mini-cat-cel-fix.html

But you have to have a **** in the exhaust to put both the upstream and downstream O2 sensors.

 

[dapepper9]

If you absolutely do not want a cat, get the big daddy O2 simulator for the downstream O2 sensor.
It will take care of any code issues.
The cheap antifoulers only last a very short time, the big daddy part will last.

http://bigdaddiesgarage.com/mini-cat-cel-fix.html

But you have to have a **** in the exhaust to put both the upstream and downstream O2 sensors.

They don't only last a short time, it's a permanent change

 

[pacofortacos]

The anti foulers only lasted a couple of months before disintegrating when I tried them.

Maybe just cheap foulers.

By far, just getting a new cat would be the way to go - much more legal too.

 

[dapepper9]

The anti foulers only lasted a couple of months before disintegrating when I tried them.

Maybe just cheap foulers.

By far, just getting a new cat would be the way to go - much more legal too.

I think you don't know what an anti-fouler is

 

[pacofortacos]

Well, I would bet I do. They tended to use them quite often back in the day when a cylinder fouled plugs.

 

[dapepper9]

Well, I would bet I do. They tended to use them quite often back in the day when a cylinder fouled plugs.

Then they shouldn't be disintegrating if we're talking about the same thing. The rustiest piece I've ever seen wasn't even as bad as an OE 02 ****. There's nothing to really go wrong with them, the simulators are a waste of cash

 

[pacofortacos]

The anti foulers are the spark plug anti foulers - where you take 2 of them, drill out one, put stainless steel wool between them and thread them together, then thread those into the **** and the O2 into the anti foulers.

Are you thinking of something else??


The ones I bought at the parts store weren't stainless or anything, just a poor cheap metal. Cheap metal and brine solutions just aren't a good combo.

The part I linked is stainless and will prevent a cel from coming on - worked perfectly on my Cali emissions 3 cat 5.9 Dakota. It worked much better than the above system for me.
Also it isn't permanent, if you would decide to go back to a cat, just unthread the O2 sensor from the part and thread it into the new cat.

I agree on the electronic simulators.

 

[dapepper9]

You're going through way too much trouble, it only takes 1 into the factory ****. They're $6. No steel wool or anything

 

[pacofortacos]

One didn't work, still tripped the cel. Cali emissions are a bit picky.
Stainless steel wool stopped the light, but they rusted out a few months later.

The 01 Dakota is gone, traded it in on the 16 Ram.

 

[road chicken]

I just had this problem with a recent upgrade to my 97 to headers and no cat and 3" Y pipe from pacesetter.. I had the downstream O2 unplugged which tripped the light. To fix it I cut out the old pipe 2 inches on ether side of the downstream ****. I capped the ends of the pipe with aluminum caps made from thin aluminum sheet held on with hose clamps. Installed the o2 sensor plugged it in and secured the whole thing to the trans to keep it from coming loose. works like a charm.