125000k’s engine light comes on and check engine light. Got car scanned and came up with all 6 cylinders misfire, no past or present codes, cleared with scan tool and rang perfect for the day, started the next morning and after 3 minutes the engine light and check engine light returned and car went into lymph mode and was shaking and miss firing. Previous owner had done plugs and coil packs, anyone got any ideas on what to do next?
Previous owner probably used the cheapest, shittiest coils and plugs off eBay. You can bet they are fake brand plugs.
Buy a genuine set of coils and plugs from an actual shop or an online shop of good reputation rather than some random on eBay. It will be pricey.
I would also buy a set of new metal intake gaskets.
Buy some MAF cleaner and give it a good clean.
Do the PCV mod. There’s a thread in the How To Section.
Make sure all your vacuum hoses are soft and sealing nicely.
Make sure the harness earths on the heads and the engine bay are clean, surfaces cleaned, bolts tighten and wiring in good condition.
Get the belt off and spin the pulleys. Check for worn or noisy pulleys. Replace. It is of note that accessory pulleys can cause misfires in Holden Tech Bulletins.