fyi castrol syntec isnt synthetic oil. although it is good oil for 3-5000 mile intervals and no redline driving.
as bob says you could have touched a sensor harness. the MAF is in that area.
unplug the MAF, ICV, air intake temp sensor harnesses, clean the contacts with contact cleaner, then use a small amount of dielectric grease on the contact and plug em all back in.
you could have also nudged a fragile vacuum hose and induced a leak.
get the code from the stomp test and see whats up.
Alusil, Dinan DME | ITG Air Filter | Eibach/Bilstein HD | 26/20 Swaybars | Iridium plugs | Depo/ProLumen HID | Optima batt. | no AC | Stoptech brake lines, Frozen rotors, brass bushings, Superblue