Car has been sitting for about 2-3 weeks in the garage but I keep it on a trickle charger (not that it should have anything to do with this).

Took it for a spin today and check engine light came on, and I'm getting the way too common P0410 code.

What is the most common issue when this code comes up on the Crossfire? Is it typically RCM or the air pump itself? When I start the car it sounds to me like the air pump is running for a half a minute or less.

 

Mine was RCM.

 

Well, if the pump is running it is not the RCM - or at least I don't see HOW it can be the RCM. It is rare, but the pump itself DOES fail at times, but with the generic code that you are getting I'm wondering.

 

I thought it could be an issue with the soldering, I've read that. Maybe I'm confused.

 

The most common cause of the PO410 is the relay located in the RCM.
Change the relay, problem goes away. That has been the case of nearly ALL of the RCMs I have repaired.

Resoldering the bad joints has to do with the Mystery No Start issue. NOT the PO410.

 

Consider switching to a float charger that will shut off when the battery is fully charged. Harbor Freight sells them for <$10 and while I am not a proponent of Chinese tools, their electronics are not as bad. I bought about 4 and keep all my batteries (two XF, lawn tractor, cycle) on them over the winter. They don't overcharge and evaporate the fluid.