Rough start

[ShionS14]

I have 1998 240sx the only mods i have on it are an intake hotshot header and greddy exhaust. the second o2 sensor isnt hooked up either. when i went to start my car this morning it started and then idled really rough at about 1500rpm for about a minute. this setup has been on the car for three years and it has never done this. after the first minute it smoothed out and idled normally. i checked the exhaust to see if any smoke was coming out and there was none, although my tail pipe did seem to build up some moisture. its about 70 degrees when i started it and not really humid and hadnt rained recently or anything. it maybe nothing but i just wanted to ask. seemed like it was running on three cylinders or was off balance. thanks in advance.

[Ni2s4s0aSnX]

Plugs and Wires probably need a changing.