on my mac exhaust, where the o2 sensors go, there are no threads to screw the sensors in, so im wondering if i can buy a cork like o2 sensor that pushes in instead of screwing in? if not then what can i do?
they should have had o2 bungs welded in from mac. i dont know of any "push" in o2 sensors because your exhaust is under pressure. you can have any local exhaust shop weld these bungs in they look like a fat washer with threads. your car is gonna get crappy gas milage and run bad without them in.
On your MAC exhaust...do you mean on the headers? Is there just a hole in the header? The O2 bung should be welded to the header like said above. Is the bung there and not threaded? or is the bung missing? In either case, it has to be a manufacturing defect. If it's missing, you can get O2 bungs from Jegs and have them welded on if you don't want to hassel with sending back the headers...or if the bungs are there but no threads, you can have them cut off and new bungs welded on too. Note that they are metric thread. M8 I think. We had to order plugs from Jegs for the extra set we put on the 68 project to accomodate a wideband sensor on the dyno (if it ever gets to the dyno...)
Or if the bungs are there and no threads you can buy a threader (tap) at the auto parts store. I believe the threads are the same as a sparkplug. I bought the threader and retapped mine when I changed the sensors.
there is a hole on either side of my exhaust about one foot down from where my headers connect to my x pipe. the hole has no threads or anything, and im not sure what a "bung" is, but it dosent appear as though i have them...its simply a smooth hole, although it does come out a bit its not like someone just drilled a hole into the exhaust....im going to call the place i got my exhaust from on monday and see what they have to say.
It sounds like the bung is there. Like you said, if it looked like someone just drilled a hole in the header, then it wouldn't be there. The bung is just the metal ring thats threaded, and welded onto or in the header. It provides structural support for the O2 sensor. THere is not enough metal in the header to hold the O2 sensor without the bung.
You can get the threads cut, or tap it yourself. Just make sure you get the right tap. Let us know what the vendor says. Sounds like that didn't tap the threads in when they were built.