Poolman.... that's a great idea. My mechanic had the intake manifold off when doing the CCV job, but that doesn't mean he checked the gasket. I suppose it's also entirely possble he didn't actually change the plugs when he said he did. I'll have to see what's in there first so I may as well check the electrodes for wear, gap and color and do a swap between cylinders first.
Is Propane OK?