I have a 03 montero limited with the 3.8 I had the timing belt changed by a local shop, and now the motor has a bad detenation problem even with 93 octane gas. It never did this before even with 87 octane. We had a 01 montero before this one and it ran on 87 octane also. There is no distribiter to adjust, so the timing must be set by the computer someway. Does anyone have any ideas what the shop changed????

 

maybe it was not timed correctly