Alright so my 2001 z24 has had the check engine light on for the past couple months and now I have to get my emission test

I replaced the fuel pump after I bought it and read about the thing with the lines getting pinched so the other day my friend and I dropped the tank inspected all the lines nothing look out of the ordinary, I also inspected all the wiring back there and again everything seemed fine I also replaced the gas cap... but that hasn't helped I am debating whether or not to pay $70 for the smoke test at a shop just wondering if there were any other problems that I could look into that dont cost too much money...or if there is a DIY smoke test perhaps...Thanks