I'm about to do a 150,000 mile tune-up. I'm planning to do a Transmission Flush, oil %26amp; filter change, change spark plugs and replace valve cover seals (front is visibly leaking). At this point the engine runs great and has never blown a code.
I know that Spark plug wires eventually degrade and that coils will eventually fail. Should I just wait until the engine blows codes, or should I replace earlier?1999 Toyota Sienna Plug Wires and Ignition Coils replacement?
i would say to leave the coils alone and just do the plugs and wires and the other stuff you plain on doing.
