2010 Kia Optima Gas or exhaust smell

After a tune-up, including replacement of all replaceable filters, including cabin filter, I kept smelling what I thought was gas, coming into cabin, through the vent, when it was pulling in air from outside. I ckd back w/my mechanic to see if it was anything related to tune-up, which he said it was not & he ckd & found no visible leaks in gas line or around injectors. He didn’t think it was gas & suggested I ck w/dealer for engines leaks and/or w/muffler/exhaust repair shop to see if it was exhaust fumes. Dealer also didn’t think it was gas fumes, & agreed I should ck exhaust system, but it still smelled like gasoline to me. I’m not a mechanic but I did some research and read that a gasoline smell can be a symptom of too high gas content corrected by tuning up the injectors to adjust the mix; blocked injectors might also be an explanation. but if that is the explanation & a tuneup could fix the problem, it would also explain why the smell started after the tune-up. I always trusted my mechanic But I went back 3x and my mechanic never even suggested that could be the problem even though I pointed out it started rt after he serviced it. Does that sound like a reasonable cause/solution? What should I do? Go to another mechanic? I pd $250 for the tune-up & don’t want to spend another $250 to fix it but other possible issues with exhaust might be even more expensive and/or a safety risk.

Get a friend in the car and ask them if they smell gas. A small amount odf gas makes a hole lot of stink. Any leak on fuel rail or injector o-ring could cause it.