Engine is F'ing up and I need help fast! Please Help

[SneakySloth14]

Okay well today I was replacing the stock air filter with a K&N air filter I bought for my s13. I took out the air box because it was all dirty and there was oily residue at the bottom? dont know from what. so i cleaned it out and installed everything back the way it should. I took the car out for a ride and i started having problems right away. First the engine seems very sluggish to pick up. it was like that before but its been getting worse. Then when i got to a stop the engine was shaking pretty violently. When i got home and popped the hood there was light smoke coming out the engine but the cluster reads normal operating temp. If you guys can please give me a suggestion of what I should check I would sure appreciate it!

[asoomal]

Try cleaning your MAF, also check if it's connected properly.