My 94 only has one 02 sensor in the exhaust.

 

just leave the one o2 sensor in, we have pretty much the best obd system out, i have a 95 and its the same, u can run straight pipes as long as you have that o2 sensor somewhere in the exhaust pipe. if u take it out or leave it hanging it will give you bad gas milage and run like sh*t. Like i said, leaving it in is okay, true Mopowar it does in fact produce A/F ratio for the engine and keeps everything in order, in 96 they added more o2 sensors to "Check"[:-] and see if the cat is doing its job and is there...[&:]
ours.. muah haha... does not have but 1. just to check for amount of oxygen in exhaust straight-up for A/F ratio.
so, leave it in, does not hurt anything, just keeps it running good.

yeah, in VA we have that too, its like a forever long test... if i am inspecting a car and it does not have a cat at all, i am supposed to call the troopers in and they give like a $5000 fine and tow your truck to be impounded until money is paid to have it re-installed...
[sm=boosign.gif]sucks, so im just like dude, here's a rejection sticker... stick a shoebox on there or something so i can pass it..[sm=innoc.gif]
im cool with dodge (i work for them...) ...if it is a Chevy that has no cat... blue lights are coming... lol [sm=bustedsign.gif]

 

How would it check a/f ratio after the exhaust gas passes through the converter?Everything that I have heard/read says that the aft sensor has nothing to do with mixture adjustment.

Could you please describe the testing procedure? I'm in Richmond. We don't have testing here yet, but my buddy who owns a shop said all the troopers tell him that it is coming. I know there are alot of areas up in Northern Va that require this as a condition for registration. Any information you could offer on the test procedure would be greatly appreciated.

 

lol it isnt a test, we just have to look for a cat installed somewhere. if none at all - fail.

i have to check on 96-up for check engine light, then Diag. it with DRB and if it says DOWNSTREAM O2 sensor something-fail

the upstream, - before cat- controls A/F ratio, the aft one just checks to make sure the cat is working effectively...

 

I'm pretty sure I have a broken cat and want to just get it removed (rattles are annoying). I don't want to replace it b/c it would run me over $500. So if I replace it with a straight pipe, I've read that you buy a sim. I've found some that are around $70, and others that are around $15-20. I'm assuming the cheaper ones don't work, does anyone have any knowledge on the different sims? Also, doesthe second sensor have anything to do with A/F ratio or any other computer related issues? Will the sim correct all possible problems (is my truck still going to run smooth)?
And, is this going to be too loud or bad? I've got a 40 series muffler SI/SO with 3" pipes i beleive.

THANKS

 

another thing to add...if your state has visuial inspections, get a heat shield from a cat and weld it in a place where a cat would go, that way it fools them on the visuial.

 

yeah, you will be fine...i have a gutted cat. I cut it open, chissled all the inside ceramic out and then welded it back up and you can't even tell i touched it. I put a sim there and my readings are fine.