I purchased this 05 Rav4 a few months back and recently started having some major issues. After driving it for a short while I start to get a major vibration in the front end and it seems like the car is constantly slowing down. When I step on the gas it will shift up and accelerate but then it doesn't want to downshift on its own. I have to disengage the overdrive and then re-engage it before it will downshift. This seems to happen mostly when I am on the highway. The vibration will make my brake peddle pulse when I start to slow down, and it seems like it went away shortly after I got off the highway and returned to slower speeds. I do have a check engine light that has came on but I have not had it checked yet. I am planning on hopefully getting to that tomorrow. When I first purchased the car and I started noticing a slight vibration only when going around curves on the highway and was thinking the wheel bearing might be going out, but now this all of a sudden started happening and has me wondering if it is something more major.