i have a '99 durango. when im stopped or slowing to stop, the "check gauges" light will come on, my oil pressure needle will drop to the negative. BUT the truck remains on, my RPMs remain normal, and the needle will jump back up reading normal pressure after about 3-5 seconds. my check engine light has been on for a while, i took it in and used one of the code readers to figure out what was going on. had something to do with an LDP. the mechanic there said it was either a problem code or something else. what do i do?