Hi all I am new here I have a 2001 Tacoma. Now I need help please. The truck began flashing the CEL because of a misfire. Then started bucking and misfiring bad. I changed coil packs plugs and wires. This fixed the problem for 3 days. Today it started bucking again. Neighbor read codes says misfiring on cylinders 1,3 4,6. From what I have read it could be timing belt. Engine is not original replaced about 5 yrs ago. Any help will be greatly appreciated.