About a month ago, my 2005 RX-8 (AT) threw a CEL with a P2070 code. After consulting my dealer and researching on this forum, I learned it’s related to the SSVs and possibly other components. My dealer initially recommended replacing "both" of them, but then said one could no longer be purchased. (This confused me—was he referring to the VDI and VFAD? I’m unclear.) He reset the CEL, and I was on my way.
I have a K&N filter, but I ruled out oil contamination as the cause. I had the dealer inspect the MAF sensor, which was clean, as was the intake tube. I haven’t oiled the filter in quite some time, so filter oil gumming seems unlikely.

The engine is running very smooth overall with no loss of power:

• Idles fine (though a bit rough on cold morning starts).
• Starts reliably.
• Revs effortlessly and has plenty of power.
• Acceleration is smooth and peppy.

Initially, the CEL stayed off for a day but returned. Interestingly, it seems tied to the fuel level:

• I drive it home, fill up the gas tank, and the CEL turns off.
• Once the tank is about 3/4 empty, the CEL comes back on.
• This on-and-off cycle continued for about 2-3 weeks.
• Continues to go on and off . ( Again yesterday today.. I park overnight it goes off. After driving it for awhile it comes back on. The goes off at night)

Now, with temperatures regularly in the 20s and 30s (NYC area), the CEL has been on consistently for about a week. Despite this, the car is running fine with no noticeable issues. (Update: it is going on and off again)
Based on this forum and other sources, it seems the likely culprits are:

1. Valves that are carboned up and need cleaning.
2. Valves that are damaged and need replacement.
3. Actuators or solenoids that may be dirty or need replacement.

I manually inspected the actuators and moved them by hand. They don’t seem to be sticking—just the usual road dirt and grime, nothing I’d describe as "gummed up." (Would spraying them with carb cleaner be worth trying?)The dealer quoted me $570 to clean the SSVs, but what if the CEL returns afterward? Should I go straight to replacing the components and avoid the risk of a repeat issue? Or should I start with cleaning and see how it goes?I’d greatly appreciate any insights, advice, or suggestions on solving this issue effectively (and hopefully cost-efficiently).

Thanks in advance!