I have a 1995 Nissan altima, 5spd manual. I recently added a cold air intake, and after doing it car runs good, untill I was checking the acceleration, and rev the engine pretty high, and suddenly I heard a POP, loud enough to hear over the high rpm, then I noticed that the idle changed, its a little rough, and noticed too that, there's smoke coming off the tailpipe(never seen that before in my car), and I also noticed that the smoke leaves a black stuff on the tailpipe. Can you please tell me what I did/broke, and how to fix it. The engine now runs pretty weak on low RPM, and runs strong on high RPM, but still makes the black smoke.
Your problem here is you're burning more fuel than oxygen, probably what happened here is you popped a carbon during the high rev and went towards the injector/s pintle holding it open or a punctured pressure regulator. I might be wrong but I'll start there.
You need a scan tool to view the serial data stream to find out what is really happening with the engine management system.