There is no way a regular person can test it that I know of. There are rebuilders that can test the ECU and repair/replace it for you.

 

Found Out that all the issues i was having was because my cat was completely plugged up. Thanks for all the help along the way!

 

good thing you caught the clogged cat. if left too long it can cause lots of damage to the engine. at least the new cat should last a lot longer now that you are no longer burning oil.

 

Yeah I'm surprised the bad cat caused symptoms of a vacuum leak. I found a nice Magnaflow cat for it for $90 that I'm eventually gonna get, for now I'm gonna just put a pipe in its spot for a little while since Minnesota doesn't have emissions testing.