Ok, this is my first post to the forum but I read it all the time.

My truck - 2001 Dodge Dakota 3.9

I have a huge hole in my drivers side small cat, and I am looking to just take the small cats out and put in a regular Y pipe. From what ive read, I should just zip tie my post cat o2 sensors to the frame rail. What do I do with the pre-cat sensors? Do they just stay in there? Is there even a spot for them in a new Y-pipe? I am curious as to what this is going to do to my mileage and power.

Does anyone have a different suggestion as to what I should do?

I really do not want to use a o2 SIMM so any other options would be appreciated.

 

If you have an SCT tuner, you can turn those off. Best way to get around trouble codes. Not that I'm advocating for bypassing emissions.

 

yes you can not sure if it will throw a code or not but all they do is tell the PCM that the cat. is working or not I don't think it has anything to do with the fuel trims

 

In most cases the downstream oxygen sensors do not delegate the fuel trims...but they will cause a catalyst efficiency code P0420 P0430. I priced out a kit to replace both primary converters, ran about $260. When I rebuilt my 4.7l I ended up welding in new converters for about $65 each.... You are violating federal law by eliminating mandatory emissions systems...(welcome to the group) so i must say Im against you doing this.... BUT!!! If you were to...eliminate the primary cats, weld in spark plug repair plugs to pull the sensor out of the pipe... That would pretty much limit your sample amount...and put your sensors working within ratio for acceptable performance readings to the pcm and not throw a code..