o2 sensor spacers

[Mike in SC]

My 2014 Mustang GT came with Cat "test" pipes. I replaced them with aftermarket replacement Cats and I can't get rid of (for any length of time) the P0420 & 0430 codes. Are the o2 spacers on eBay the answer? Will it make it run too lean? In the future I will be getting a power tune but I heard that most of the tuners will not shut off the downstream sensors. Any input appreciated.

 

[07 Boss]

My 2014 Mustang GT came with Cat "test" pipes. I replaced them with aftermarket replacement Cats and I can't get rid of (for any length of time) the P0420 & 0430 codes. Are the o2 spacers on eBay the answer? Will it make it run too lean? In the future I will be getting a power tune but I heard that most of the tuners will not shut off the downstream sensors. Any input appreciated.

You seem to be a little confused. First off you're talking about turning off your downstream sensors but then also asking if you run spacers you're worried about running lean. Following this logic shouldn't you be worried about shutting them off completely? Anyways, neither nor because rear sensors have nothing to do with engine management.

How did you not have the light on before when you had test pipes in?

 

[Mike in SC]

Maybe I wasn't clear as I could be. I did have the chk engine light and the codes with the Cat elimination pipes. When I put on the replacement Cats the lights and codes went away for 2-3 weeks. Then both came back and I could clear them for 2-3 days. Now it's constant. Like I said, somewhere in the future I am getting a power tune. The tuner may or may not want to turn of the o2 sensors. In the meantime, do these spacers work or is it snake oil? That's the main question .

 

[travelers]

The rear O2s only monitor the efficiencies of the cats. The front O2s are for air fuel ratio.

 

[RED09GT]

They work on my SVT focus. I put on a high flow cat pipe after the stock converter disnitegrated and had the P0420 code for a couple years. I bought one of the spacers about a month ago then scrubbed the code and the check engine light has been off ever since.

 

[Mike in SC]

red09GT, what length did you use, 45mm or 55mm? I believe that I have room for either length.

 

[RED09GT]

I got mine from Amazon from evil energy. I believe it is the 45mm.

 

[07 Boss]

Maybe I wasn't clear as I could be. I did have the chk engine light and the codes with the Cat elimination pipes. When I put on the replacement Cats the lights and codes went away for 2-3 weeks. Then both came back and I could clear them for 2-3 days. Now it's constant. Like I said, somewhere in the future I am getting a power tune. The tuner may or may not want to turn of the o2 sensors. In the meantime, do these spacers work or is it snake oil? That's the main question .

I have mini-cat spacers and pass OBDII smog testing and never throw a cat code. Going on 2+ years now. Never tried the regular spacers or anti-foulers but sometimes they can be hit or miss. I also have a 3-valve and I seem to remember the coyote motors were a little harder to fool. I have in the past built my own cat sims from few bucks in Radio Shack parts and they worked flawlessly for a couple of years too. But again it is my understanding that this does not work for the coyote.

 

[MrAwesome987]

I modified and used "spark plug non foulers" from oriellys. I used two on each sensor on my 09. It worked for a while and then the light came back. Later I got the car Dyno tuned and the tuner turned them off.

 

[06 T-RED S/C GT]

When the tuner shuts off the rear 02 sensors in the tune, it just prevents the engine light from coming back on, but you will still need the mini cat spacers that 07 Boss mentioned in his post in order to pass the OBDII emissions test if the spark plug non-foulers don't work out for your particular application

 

[MrAwesome987]

I live in a state of freedom thankfully, so I could care less about passing an emissions test lol

 

[RED09GT]

I was actually looking for the mini cat ones when I bought the spacer and ran into a webpage talking about how the EPA was cracking down on people selling them. I could only find a couple sellers that were in the Ukraine, Asia, or some other part of the world that requires a boat ride for the parts to get here. The spacer worked for me so good enough.

 

[Mike in SC]

I also live in an emission free state but all I want to do is get rid of the engine light. Gonna give the spacers a try. If they don't work then I'll wait for a power tune and hopefully the tuner will shut them off.

 

[MrAwesome987]

We actually live in the same state, now that I read your name lol

 

[Mike in SC]

Awesome,
Who did your Dyno Tune? Pro Dyno in Ft Mill?

 

[MrAwesome987]

Yep, Pro-Dyno. Had it done about a month ago.

 

[Mike in SC]

That's where I'm going for mine. Thanks for all responses.

 

[JEWC_Motorsports]

The sensors are probably trashed. Id start there.

 

[Riptide]

On my 2014 car the spacers did not let the monitors pass. The tune had the CEL nulled out so I never got a code however the car would never pass an OBD2 emission test with or without the spacers.

There are ways to get around these issues however it has gotten much harder. If you can write your own tune you may be able to do it however the vendors will not set the tune up to pass without CATs.

 

[07 Boss]

On my 2014 car the spacers did not let the monitors pass. The tune had the CEL nulled out so I never got a code however the car would never pass an OBD2 emission test with or without the spacers.

There are ways to get around these issues however it has gotten much harder. If you can write your own tune you may be able to do it however the vendors will not set the tune up to pass without CATs.

You failed because of the tune having the sensors turned off. Didn't matter even if you had cats, if the sensors are off it will not pass.


And OP, use the mini cats, not spacers.