2003 Mazda Protege DX

I'm new to this site and have no expectations that anyone can help me with some info. But recently I was driving down the highway and started switching lanes to the middle Lane to allow the people getting on the highway to merge on safely, as I started to merge over there was a metal sign in the middle of the lane (My car is lowered) and by the time I could react it was wedged under my car. I pulled off the road on to the shoulder, got out of the car and looked and all my oil had leaked out of my car because it ripped the oil pan clear off my car, not only did it rip off the oil pan it but it also took my oxygen sensor with it as well. Needless to say I had it towed back to my house where I put on the oil pan and oxygen sensors (I say sensors because I figured if I'm gonna buy one I mine as well replace the other one that didn't get touched) I unplugged the battery for about 5 minutes an plugged it back in, and the light was off. I took it for a test drive about 10 miles (I was always told it would go back on within a couple miles) and it stayed off. I was thrilled. Well I get into my car this morning an start it up, and it's still off! I'm ecstatic, I'm almost certain I could go take it to get it inspected. So I drive it to go get breakfast just to put a little more miles on it, and on the way back home BAM that yellow light from the devil was back ON! any ideas? Maybe should I reset it with the computer? Would that make a difference at all? I work full time and only have this vehicle to get to an from. But I don't wanna take it to a shop an they tell me I need to do A.) B.) And C.). I feel like slot of mechanics are crooks and take advantage of people who don't know much about vehicles in general. Please if anyone could help, or even just give there opinion on the matter. Also if anyone needs any pictures at all to have a better visual please let me know and I will take some


(u_u) ...zZzZzzz
Maybe something else got affected and could be causing the code. First, scan and figure out what the code is, do some research on it and take it from there. An autoparts store will scan your check engine light for free. When they attempt to sell you parts to fix it, decline with (insert reason here).