Getting a check engine light on my '98 328IS. AutoZone reads codes that indicate it could be a vacuum leak, bad valves, or bad cats. There is that familiar hot ticking sound coming from the exhaust after you drive it ..... Does that indicate bad cats, or is it a symptom caused upstream? I think the Bentley manual says this car has lifetime cats, so I suspect the cause is elsewhere. Anyone with a similar experience? Any easy way to sort this out yourself? Thanks to all.
