Hey Guys,

I converted to a true dual a while back and it has been throwing an O2 code pretty much ever since I did it. I think it is because the sensor behind the cat isnt sensing as much flow as it used to because the pipes never meet together so it only gets half the flow. Is therea way to correct this or will i have to re-do the entire exhaust and go back to a single pipe? I am probably going to get a new muffler anyways...Im thinking magnaflow dual 2.5 inlets/outlets. I just dont want to spend money getting a muffler ill have to get rid of if I need to go back to how it was.

Thanks
Chris

 

you can buy an electronic gadget (i think its a SIMMs not really sure) that sends a signal to your PCM making it think you have a perfectly working cat.

 

Get some O2 simulators.

 

im confused here. do you have the stock exhaust manifolds in there still?(those have a cat on each of them,with a 02 sensor). so from there it goes straight pipe to the muffler correct? no h or x pipe? you should put one of those in if you dont,they are put into balance the exhaust flows with one side to the other. how many cats do you have (if you did get headers), from what you wrote it sounds like you have 1 which doesnt make sense if you have true dual setup. I know on my stock exhaust manifolds the 02 sensor isnt behind the cat its right in the middle of it. can you explain your setup a little more.

 

I've been doing my own exhaustsfor about 25 years (since about 16 years old and I got a '73 Nova 350 SS) and have ALWAYS used an "H" pipe on my duals. Cut and weld one in and see if the problem goes away.
You could also use the "non-fouler" trick as opposed to buying simulators...