Hey all!

Been a bit. I've been driving the C32 AMG as a daily driver for a few years now and she's been showing her age as of late. Since 2018, I've replaced just about everything that can bolt onto the engine and more. We're talking injectors, intercooler pump, water pump, transmission... a whole lot of maintenance at 200,000 miles of driving bliss. Most recently my factory 722 transmission stopped engaging, so I went and found another one to put in, but it stuck itself in limp mode until I replaced the shifter mechanism from a junkyard find W203... it's the peppiest it's been in years now!

But that's not where my current issues lie.

I know I'll have to replace the alternator soon, and that I have a slew of electrical issues likely the result of a busted clock spring and my Front SAM unit. None have been persistent enough to warrant a complete electrical system overhaul, but I'm getting closer to that with my current issue. I've scoured the forums for some quick things I can visually check for, but I've got a CEL on now because of the infamous Gas Cap issue. Except... I've replaced the gas cap twice now, and whatever leak in this system isn't from that particular spot. I'm not leaking from any of my vacuum lines in the engine bay, but this issue started around the same time I had my fuel pump replaced about a year ago... one that now registers my fuel tank as "full" at 11 gallons, not 16. I'm wondering... I've never dived into fuel system stuff, but I'm imagining the shop that did my fuel pump didn't properly connect something, hence both the leak in the system throwing the Fuel Cap warning, CEL and returning sub-par MPGs. I have no under car leaks whether it's been stationary or I've driven it hard. The strange bit is I once had some water on the floor board in the back seat, but that was after driving through a rather deep puddle one day (SoCal isn't prepared for rain).

Wondering if any more mechanical folks here might be able to point me in the right direction.