So, I'll give a quick deal to a long story to see what you guys think of how this panned out.
Little background; car is a 2010 2LT, 44k~, Certified Used; all the factory warranties that are still there; are. Car has a K&N Drop-In, ZZP Hardpipe, and an Option Racing Catback. Nothing else has been touched other than me changing the oil and doing the coilovers/suspension parts.
Ok, so...Thursday Jan 31...had a CEL pop on. Went to have it read...car chucked like 32 DTC's leaning from heated o2 codes, to EVAP, to MAF, etc. Cleared them (btw car was idling like crap, MPG's weren't besting 20~ even cruising on the HWY). Called a buddy of mine who works at a local dealership who pointed me in the direction of a fuse titled "ENG VLV SOL"...and I really was "SOL". Pulled the fuse...it was blown. Simple fix, YAY! Swapped the fuse, car ran great...fast forward to Saturday, leaving work around noon (yeah, bankers hours...wheeee), funky idle kicks on again...CEL is back. Awesome. Go to the parts store, same situation. I think, ok, now I've got a wiring problem...it's popping fuses. I check the fuse...it's good...WTH?
As I put the fuse back, I realize that there is nothing holding it in.
I get home with that awesome 18~ MPG's...rip apart the factory fuse box to find out that the terminals are no where to be found on the motherboard and pin F8A 17 and F88 were non-existent. Checked everywhere...found nothing. Junkyards had nothing as well (since the '06 Ion fuse box internals are different I got boned and wasted $17~ there as well). Turns out, no one locally sells anything like that...so, the soldering iron was whipped out and went to work. Removed the DRL pin from the top of the motherboard, soldered it in down on the F8A/F88 location...reverse angrily...and; car runs great.
Crappy part here is the dealership wanted NOTHING to do with the situation...basically quoted me for an entire wiring harness/fusebox swap.
Eff that, noise.
So...mean letter to GM I go