f150harleytruck7

i have a 95 civic ex w/d16zc, i put a used s20 transmission in and now the car sounds funny when vtec kicks in and it wont bark any gears and it seems slower, the check engine light came on the day after i put it in, i turned the car off and back on and it has not came on since. this tranny has a s20 sticker, but my other one had i believe a yf4 or yz4 sticker, i will post the correct sticker later today, could vtec have screwed up or somethin?