Rep Power: 0

hello guys I have 04 two door ex with the vtec 1.7 and it keeps burining up ecus I have changed the dash harness I have also changed the engine harness and still drive for thirty minutes and bam limp mode tach don't work and barely runs please help guys where do I need to look first alternator or what im just floored by this and don't wanna keep throwing parts at it

 
Rep Power: 518

Loose alternator mounting bolts.... or poor engine grounds. Loose alt bolts is by far the most common cause. Ever since the alt was last removed, like when the timing belt gets replaced.