Getting a miss on cyl 3 and 4. Probably a vacuum leak(the one that gave me a scare in TX), but going to take this opportunity to change the plugs (if needed) and pop the valve cover gasket just to get a general idea of how healthy this lump is. Check the plugs, and the valve clearances, check for oil leaks that sort of thing. What obvious tune up thing am I missing? should I bother cleaning the MAF or intake in general? the paper filter is fine for now.
Update with photos:
Spark plugs were old and ashy (mostly) with some oil residue around (and in?) the coil packs to varying degrees. Cleaned them up and let’s see if it improves. The valve cover gasket seemed alright, but already had the replacement ready. No obvious red flags with the cams, so that’s always good.
hopefully I’ll get a bit more mpg and power, but mostly hoping the CEL goes away.