So,i had to tinker, and I messed it up. I had a custom off road y pipe made for my pickup, then installed two O2 bungs, because I thought I only needed to run the front sensors. Well, the mileage blows, so i decided to use jumper wires to hook up both connectors to one sensor. (should have 4 sensors, only running 2). I know, retarded right? I didn't want to have to install 2 more bungs. Now the truck is missing, and running like crap, but I'm tired of running it in closed loop everywhere, with no sensors hooked up. My question is.. I only need two simms, right? Just for the after-cat sensors, and then leave the other two sensors I already have installed, and hook them up as the 'front' sensors? Thanks...

 

Wow, thats a mess .... I do not envy you. I hate california and its 3 cats.

If it were me I would put the wiring back to its factory setup. Then determine which O2
sensors tell the computer that the cats are working and which sensor(s) actually handles
air/fuel ratio. O2 simm the cat sensors and hook up the O2 sensor that handles a/f.
My truck only has two; The up stream handles a/f and the downstream just tells the
computer that the cat is working, so that one got a simm. Doing it my way may require
you do reinstall a cat or two, but thats the best answer I have.

 

Do it right and reinstall all of the O2 sensors in the correct places.

It isn't the easiest way, but it is the best way. O2 sims won't do you any good if the front O2s aren't reading the correct A/F ratios

More than likely the 2 sensors wired together are sending multiple signals to the PCM and causing an enormous freak out.

 

Yeah, thanks for the help. I hooked it back up like factory but without the cats, and its runnin better now... i just gotta quit tinkerin with crap:P

 

Either that or the computer doing what it was designed to do, and drawing power for two sensors, when there is only one to draw from, and there isn't enough stable voltage coming off a single sensor to do the work of two.


Holy run on sentence.

 

Don't stop. Not everything you do is going to work but it doesn't mean you shouldn't do it
anymore. :-D

 

Buy 2 new cats and install the O2 sensors before and after each as they were originally. Bolt on Cali cats are now available from Magnaflow.
That's the BEST way to get your truck to run the BEST.