I have a 95 Dodge pickup truck 4 wheel drive 1500 and one day I stepped on the brake to hard and my RPM guage went down to zero, came back up, and the engine started running funny like it was going to die. So now my RPM guage goes down then up by itself, the check engine light comes on after it does that.So I think its made my gas run sweet and I have black smoke coming out of my tail pipe. Just wanted to know if anyone knows what I should do bcause I cant figure it out.. Thanks.