So I got this problem that I've been unable to resolve and no matter what I do it gets worse... I have a 91 camaro 305 tpi 5.0 v8. Its have a issue sems like either fuel intake or air intake that started when I changed the air filters. when running and in park the rpms ride at about
2k and dip down to about 1.5k in drive. While driving the rpms will make a sudden quick dip then back up to normal while driving at a steady speed. Now its doing something new when it'll fall in rpms and if I press the gas it'll drop and not accelerate and when I release the gas it goes back up to where it had been. Its almost like I'm hitting the breaks instead. I have no idea what's happening

 

i got it back from a mechanic he said the oil pan is cracked, then computer isnt communicating with the rest of the car like it should be, the last owner bypassed the tpi cooling for some reason... the air intake hoses are fine theres no extra air being taken in. he said it was the idle air control valve but ive driven 100 miles since hes put it in and its hasnt made the least bit of difference