I have just repaired the engine wire harness, new ignition wire set, cleaned the spark plugs and one new coil pack. After all this my car still have the symptom of struggling going uphill. It will struggle 20-40km/hr & very slowly pick up speed. Can any you help me diagnose?

 

check the spark plug cables
or you just might need brand new spark plugs

 

Thanks as I mention I already have a set of 4 Ignition Wire Set or new Karlyn Spark Plug cables but I did not replace the spark plugs, just cleaned them with brush only? I may do as you suggest. But meanwhile i read it could also be the knock sensor (as I use unleaded fuel rather than Premium), is there an additive to supplement this into the fuel tank?

Also the MAF (air mass) sensor, can I test it by unplugging it & driving the car uphill & if it dont struggle, then its the MAF. Do they sell the sensor only from Bosch without the tubing (cheaper)?

Also the fuel filter, is this also a culpril?