nonfouler o2 trick

FlaglerMegacab4x4 · Nov 8, 2013

ive got 2 bad rear o2's and im looking into the nonfouler trick anyone know how it works and how many I need to do it

ATXHEMI · Nov 8, 2013

You will need 2 for each side. Drill one out screw into other one. Screw both into pipe and reinstall o2 sensor. Some people put steel wool on them but I didn't. My cel come on every now and then.

FlaglerMegacab4x4 · Nov 8, 2013

what do you mean drill it out? like bore it oversize to slip it over the o2?

FlaglerMegacab4x4 · Nov 8, 2013

also if I do this will it cause the engine to run lean or rich? I do have a dsp on it

Trupiano · Nov 8, 2013

Yes you have to bore the hole out bigger so it fits. No it wont affect anything to do with your air/fuel ratio.

Your fwd two O2 sensors control your Air/Fuel ratio. Your rear two only ensure your catalytic converter is operating properly. They're probably only reading bad, because you put true duals on and they're reading too much hydrocarbons that are not being burned off any longer.

FlaglerMegacab4x4 · Nov 8, 2013

ok thanks a lot! could you explain why/how theres more hydrocarbons being burned? The light came on about 2-3 months after I put my duals on, Im getting a 420 but I know its my cat because ive replaced my o2's with bosch and the code changes so I know I need Chrysler o2's just don't feel like paying the stealership fee for nothing.

Trupiano · Nov 8, 2013

When you put on the duals, did you remove your cat, or change it to a higher flowing one? Or possibly change your headers?

Because honestly that's the only reason why they'd read higher... meaning the catalytic converter isn't getting to burn off as much of the residual fuel, and the sensor is picking up that excess and reporting it as a check engine light and a code.

When I did my headers and higher flowing cats on my 05 this happened. Due to the fact that my cats weren't as efficient and more was passing through to the sensor.

Figured the true duals in your sig meant you didn't have cats. But if you haven't changed anything upstream and the cats are in the same place... then I'm not entirely sure why they'd be throwing a code.

BigSloth · Nov 8, 2013

Changing the exhaust to true duals usually doesnt alter the A/F ratio. What actually causes the P0420 in most true dual setups and header installs is actually the location of the sensors and the new exhaust flow path.

From the factory, the PCM is calibrated to the signals the o2s should read with them in the factory location, with all the exhaust flowing through the factory tube down the factory path. When you start to change that path, tube size, distance between sensors, distance between cats and sensors, etc the data that the o2s will give off starts to vary. The truck isnt actually running any differently, but the DTC detection logic interprets the difference in data as a catalyst efficiency problem and throws the 420.

Now when you throw codes for the front o2 sensors, you will have a change in A/F ratio. but the catalyst effic. codes in your case are usually because of the new location of sensors, or the new flow path.

BigSloth · Nov 8, 2013

Ive never honestly payed much attention to my exhaust so I dont know if theres one or two cats, if there is only one cat, that is why the light is on. Both pipes need a cat, otherwise what Trupiano said will occur, the cat isnt doing its job(because its not there) so the code sets.

FlaglerMegacab4x4 · Nov 8, 2013

I still have cats and stock manifolds, the o2's are in the stock location they didn't have to be moved in order to run the duals.

Trupiano · Nov 8, 2013

And you said you replaced those sensors? If so I have no idea. But the spark plug non Fouler trick will work for the O2 sensors.

El Phono

FlaglerMegacab4x4 · Nov 9, 2013

Yea but I got Bosch from oreilly and I cleared the codes and the cel was gone for a while but came back under a different code something like voltage too high or too low some BS like that and I figure that's just because dodge dosent like Bosch and I know how picky the electronics are on these trucks so I returned my Bosch and put the originals back in and of course the good ole 420 came back. Thanks for all y'all's help I got CQ today I'm sure Trupiano knows all about that lol so I'll get to this Monday and let y'all know how it goes

hemihustlin · Nov 9, 2013

Get NTK O2 sensors they will work

TheSatinPumpkin · Nov 9, 2013

6 years MIL free.
http://www.ramforum.com/f50/lt_headers_cats-2114/#post44418

chefred112 said:
move the **** down appropriately and use plug foulers with steel wool stuffed in it..works for me..

Redtruck-VA · Nov 9, 2013

It isn't magic. The O2s operates 0-1vdc each time the voltage changes it is called a flip. There are two circuits in both front and rear O2s, the heater circuit which brings the sensor into it's operational range where it is most accurate and the element which as it is exposed to different concentrations of oxygen causes the flip that is counted by the PCM. The front O2s signal is what gives the PCM the information it needs to adjust the AFR up/down. The PCM also counts both the front/rear flips. The rear O2s also has a heater circuit. The PCM counts the rear voltage flips, as long as the flip count is less then the front count then you will not have a DTC. This is why the "Non-fouler" work. The heater circuits is what generates the "high voltage" code and is generated when the heater element is burnt open or unplugged. Good luck..

FlaglerMegacab4x4 · Nov 9, 2013

Thanks for the instructions SatinPumkpin and I appreciate the explanation Red

FlaglerMegacab4x4 · Nov 10, 2013

Ok so I just finished installing and driving the truck the cel didn't clear automatically so I did it myself with the DSP so I'll just have to see if it comes back

FlaglerMegacab4x4 · Nov 10, 2013

Also when I cleared the code the codes I had were 420 562 and 700 the last 2 are probably due to the bad o2 sensor correct?

FlaglerMegacab4x4 · Nov 13, 2013

hey all just a heads up the nonfouler trick work great thanks!

Redtruck-VA · Nov 13, 2013

sweet....

nonfouler o2 trick

Senior Member

Senior Member

Senior Member

Senior Member

Registered User

Senior Member

Registered User

Senior Member

Senior Member

Senior Member

Registered User

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Similar threads

Forum statistics

Share this page