For a month or so, my 242 turbo has had a hitch in her giddy-up for 2-3 miles every morning, sputtering slightly, but always going forward. It is fine the rest of the day, whether cold or hot start. Just today, the cough happened on the way home from work, and has not quit since. With just a little gas, I seem to keep it fairly smooth, but it has no pickup at all, actually losing rpm the more gas I give it. I thought it might be a simple spark plug, but the car parts store guy told me it's likely the head gasket. Does anyone know the cost of this? Is there anything else I should have looked at while the engine is apart? Thanks