Does anybody know where I could find an adapter that would screw into my O2 sensor bung that would let me check my backpressure? I'm wondering if I'm losing anything to my 92000 mile old cat. It hasn't done anything noticable. Really, I'm just looking for a reason to replace it with a high flow cat, or if I can get good readings without it then just delete it. There's no testing here in S Fla, so if I can still run clean it doesn't matter to me how it happens. Assuming I could even find a place to test it for me, that is.
I've already got a magnaflow muffler, so I don't have any restriction there. I'm thinking the cat would be the next biggest offender.
Anybody know where I could get an adapter so I can get on with it.
Thanks, Gas.

 

I've never seen anything like that... but that would be pretty cool to find if they make something like that. To be honest, it is probably cheaper to just to chop it out and do what you want.

 

Try Google. "exhaust back pressure test kit". Easy.

 

This is the one I have http://www.automotivetoolsonline.com...B_p_13336.html

 

I just drill a small hole into the pipe, and insert my test gauge probe. Works great. When finished, either weld it up, or, put some JB weld on it to seal it back up.

 

I thought the o2 sensor was just std 18mm spark plug size. With that in mind could you not use your basic compression tester? My 97 fsm does not list a max. psi but I noticed my friends 08 Zo6 lists a 2 psi limit measured at the pre-cat o2 sensor before changing the cat?

 

At idle it does not want to be above .09 Bar. At 2500 rpm it does not want to be more than 2 1/2 PSI. A compression tester is not that accurate at those low pressures, and may not be made to stand up to the heat.

 

Thanks for the info guys. never seen anyone test back pressure before.

 

Sure way to find a bad cat.

 

A vacuum gauge will tell you everything you need to know about exhaust restriction,or the general state of your engine.Best 8$ you can spend at harbor freight.