Avensis 1.8 Vvti 03 Chugging Until 3800 Revs Smoking/coil Pack Failure

[Auldy83]

My car is smoking more than usual, its lumpy until just under 4k revs then it takes off like theres nothing wrong with it, its not overheating infact it seems to struggle to heat up and what ever the problem is its causing the coil packs to fail. No mechanic thats worked on it has a clue what the problem is and I've been to quite a few now.

Heres what the diagnostic came up with:

camshaft position sensor a circuit

catalyst system efficiency below threshold

idle air control system

igniter circuit malfunction 1,2 & 4

ocv circuit malfuntion

I noticed the oil light flickering on and off when there was plenty of oil in it, the car goes through a lot of oil could it be possible the oil lines could've become blocked? There's 150k on the car.

Any help would be greatful I'm very nearly at the end of my patience.

[ToyotaAuris]

Idle air control valve. Thats whats causing it to feel like its misfiring. I have same problem on my VW at the moment but doesent really annoy me because once the cars moving its fine. Could also be camshaft sensor.

[Auldy83]

Iv already been down the cam sensor route but nothing changed, I would like to ignore the problem myself but iv been through 2 coil packs in 2 months so i can't ignore it I don't even drive it now.