Please help! 2-3 weeks ago I hit a pot hole, right after I hit it, it started shaking real bad and wont stop. Now every time I start the car it shakes real bad and it sounds like if its hissing and the check engine light came on. I don't know anything about mechanics but was told it may just need a tune-up, but am scared that if its been this long and hasn't stopped and I haven't taken it to get checked, because financially I haven't been able to, that it may become a big engine problem and wont be able to afford such a major repair. Please help!