hi everyone have a really bad idle, tried everything coil packs changed, sparkplugs changed, aac cleaned, fuel filter changed, air flow meter cleaned. i haven't changed the fuel pump but don't think its that could it be my cas{crank angle sensor} or injectors, only happened about 6000 ks past timing belt change. Please any help cant find the answer anywhere. By the way it shudders every 30 secs or so on idle only, boosting is fine no probs.