As you can tell by my sig. i have an 89 formula 350. I was just wondering if it is ok to just take out the two catilic convertors and put straight pipes in their place or is there an o2 sensor or any other sensor futher down the line that would prevent the car from working right. I know i have one 02 sensor for sure and im pretty sure it is before the catilic convertor but one of my friends said there might be one behind the cat. Also would cutting out the cats hurt the performance of the car in any way. thanks for the help my car is still in jacksonville getting the freeze plug problem fixed or possibly broken head gasket which sucks but im always thinking further down the line.

 

anyone have any ideas

 

one o2 sensor in the drivers side manifold, unless i'm mistaken
its an older obd i gm vehicle so they havent yet placed an o2 sensor after the cat

you may have a.i.r. tubes running to the cat, but i'm sure u can take care of that

cutting out the cats will improve performance, since they are usually restrictive to exhaust flow, but will also increase your emissions, so unless u can pass inspection without emissions then dont do it

 

yea what he said. it will improve some performance, but if you go for emissions you wont pass.

 

what are these air tubes you are talking about and how would i go about getting rid of them i think i have seen them before just dont know where they go

 

Theres a belt driven pump that pumps air into your exhaust manifolds during open loop and to your catalytic converter(s) in closed loop. To get rid of them, remove the entire AIR pump system (you will need a new serpentine belt), get new headers that have no AIR holes, and get a new exhaust system that doesn't come with a hole for the catalytic converter tube.

 

we say AIR, or A.I.R. because the system is called Air Injection Reactor
by injecting air into the exhaust manifold we can get secondary combustion from the unburned hydrocarbons which helps heat up the o2 sensor and catalitic converters to operating temperatures, letting the system get to closed loop faster, then when in closed loop, simply feeds the cat to clean up the exhaust and finally, under deceleration with carb'ed vehicles, the AIR pump, should pump air into the carb to compensate for the rich surge

more info than many care to know

 

wow i had no idea that cats were so complicated. would this cost a lot of money to do it the right way and where could i get these parts to make it work.

 

The only expensive part is the new headers without AIR holes. The rest is simply removing the old AIR components really.

 

cool that isnt to bad do i need to plug a hole on the engine block or head or does this air tube start at the exhaust manifold

 

Just the exhaust manifold. If you can find a way to plug those holes then you are set and don't need new headers, but the holes are pipe threaded so don't expect your common bolt to work.

 

what about changing the belt system do i need to do that because from what it sounds like it is only a pipe breaking off the manifold and has nothing to do with belts correct me if im wrong and if i do have to change belts is that expensive

 

You do need to change belts but its not expensive at all. This is an article on how to do this. http://www.thirdgen.org/newdesign/tech/serpentine.shtml Use the top picture for referance as the bottom picture is missing the power steering pump.

Also, for your purposes (removing the cat) you don't NEED to remove the entire AIR pump system, though I would recommend it because without the cat the AIR system is next to worthless for smog fighting. You just need to do something about the AIR pipe that leads to the cat.

 

One of my friends said if i take a shovel and drive it into the ground and then take one of my cats and run it through the handle of the shovel i could gut out the inside of the cat so it would not restrict the air at all. Is this true or possible or just pure stupidity.

 

I guess thats one way to do it. Any way you want to chip out the insides of the cat will work. An empty cat doesn't flow as good as a straight pipe though, so I'd recommend replacing it.