Hi, I want to install two O2 sensor eliminator..one on each catalytic....?should be installed before of the catalytic or after?... Any tips,please. Thanks

 

You can't really eliminate the upstream ones without, well, not being fuel injected.

The downstream you can space up enough to usually fool the PCM. Use spark plug non-foulers. There are "02 simulators" for sale out there....I've never researched them but they're still only going to work (if they do at all) on the downstream locations. You absolutely need the upstream ones as your truck needs real-time data on the mixture to run properly.....nothing can simulate that.

 

Thank you for your response and observation...it makes a lot of sense.

 

Here's the tip................."Don't"...........

 

Before you do, what are the reasons you want eliminators? Are you gutting or removing the cats, or are you leaving them intact and putting eliminators in because you are getting check engine lights?

If gutting or removing, then eliminators, or leaving the original sensors and using anti-fouler adapters will work. All the rear, or downstream O2 sensors do, is measure the exhaust to tell if the cat is working or not. They have no effect on the running.

If your complete cats are still on and you are getting a check engine light, you have a problem with the cat being plugged or melted. That needs addressed first.

Fo me, if I were going to take the downstream sensors out of normal service, I would want the cats gutted in case they ever started plugging, since you would have no sensor to tell you about any problems with them.

 

Thanks, I'll keep that in mind as well.

 

Thanks again for taking the time to respond to my concern. I got this 2007 F-150 Lariat from my nephew just a month ago. As he told me in the past he had already replaced the cats. But after some time, they removed it because according to him it caused problems again. At the moment I look for the cats and I see them in their place, and that's why I don't understand why he says that cats was removed it. The truth is that when we put the obd scan it gives me error of P0 420,430 P0 171,PO 174. Bearing that in mind, that is the reason why I was asking about replacing the upstream ones with regular o2 sensor, but the downstream ones with o2 sensor eliminated. idea, I don't know if it would help. Thanks

 

Spacing the downstream units out of the flow with non-foulers has a good chance of getting rid of the 420 and 430, that's it