long tubes no cats, mods in sig, seems to be blowing black smoke out of tail pipes during WOT runs. Popped a couple of codes for bank 2 sensor 1 O2 now it seems like I have a dead cylinder? I was thinking that I could have fouled a couple of spark plugs but I am not sure and have yet to pull a plug. Is black smoke normal for uncatted cars or am I in fact running pig rich??

 

I would start with a new pair of AC Delco o2 sensors and a new set of NGK TR55 spark plugs.

 

Yeah definately new plugs and 02s, sadly that set of TR55 iridiums that are all fouled up now only had 1k on them but whatever. I started pulling plugs today to see what was going on and bank 1 looked GREAT...bank 2 not so much. I do have another question tho is Delphi made my AC Delco?? I found a great price on Delphi but wanted to make sure before I bought them.

 

As far as I know, Delphi took over after AC Delco, both are OEM equipment. Don't know the reviews of Delphi o2's, but I have never heard of any bad things about AC Delco, that's what I would get if I were you, if you have the cash.