cracked up pipe cause richness?

[05sleeper]

So I've been fighting this rich spell it's been having and I've been ruling out some things but found that my Perrin catless up pipe was cracked and leaking by the flange. Could this cause the car to run rich as well? I've replaced every single vacuum hose and upgraded hoses and gaskets and running low 10 afr's and black smoke under hard load like tons of black smoke haha. Did compression and leak down test and was perfectly fine. Was tuned and tuned doesn't stay (Cobb protune lasted a day, sent me another map lasted a few hours just keeps going back to super rich). Fuel pressure is 43.5psi at idle. Have every bolt on besides turbo and injectors. Any ideas would be great thanks

[That Guy 2-1]

Yes. You'd introduce air into the exhaust flow that induces an artificial excess of O2 into the stream that is read by your O2 sensor, so your PCM will give it more fuel thinking it's running too lean.

[05sleeper]

Well one thing I guess I should of mentioned was I was tuned with no rear o2 sensor since I put my wideband there but thinking about putting it back in when I get tuned again. But you think it would effect the first o2 sensor in the header?

[That Guy 2-1]

Well one thing I guess I should of mentioned was I was tuned with no rear o2 sensor since I put my wideband there but thinking about putting it back in when I get tuned again. But you think it would effect the first o2 sensor in the header?

 

2nd sensor is only used for emissions; to check if your catalytic convertor works ... so no

[05sleeper]

Ok so fix up pipe and hopefully that'll bring me back where i need to be or it's just another thing crossed off the possibilities haha