02 Tahoe: Black smoke, random misfire, low mileage

[admiralwalnut]

Hello, I have a 2002 Tahoe 5.3L 2wd. It starts fine. service engine soon light is on or sometimes flashing. poor acceleration. the more gas you give it the more black smoke comes out. The computer said it has a random misfire. I am getting about 8 miles per gallon. give or take. I am thinking the crankshaft position sensor and the oxygen sensor? I grew up on the farm and I am comfy working on vehicles. Thank you for reading!!!

AdmiralWalnut