i'd replace oil pump. Remember, you have to get rid of your old exhaust system and buy a new one. The new one will not bolt on right because they don't make exhaust for hybrid...so you need to take it to a muffler shop and have them "custom fit." I went through the same shit. I didn't know about exhaust not being bolted on right...and had to spend almost 200 bucks to have Muffler King install it. Another uninformed mistake I made!