Wtk: hr15 problems plz help (pos)

[concept2]

Hr15 problems plz help... starts in about 3 or 4th time, engine holds back while trying to accelerate and exhaust smells terrible. i kno a bit about cars but a this point this prob eludes me. the following things were changed, air filter, oil and filter, spark plugs twice, coilpacks twice and airflow sensor. still the problems exist so when use the diagnostic scan the same code keeps appearing as before, P0300 multiple cylinder misfiring. after looking this up there are quite a number of thgs can be wrong. can anyone quide me plz.

[medalist]

Have you checked anything with regards to the fuel system? I know for a fact when a sylphy with the hr15 was showing similar signs of loss of power, amsoil performance improver was added to the tank and it regained the power.

[concept2]

I did....that didnt help at all

[Bamboo boy]

What about oxygen sensors

[TurboSingh12]

Fuel,Throttle body can cause it.