Sorry for the delay.
If you are getting P0171 and P0174 only since the plug/coil replacement that is going to make it very narrow for possibilities. The vapor hose on the intake duct is not likely to be an issue on this one since that will normally give you a P0171 and P0175 (rich condition) since you would be drawing in fuel tank vapors if that were the case here.
Regardless, checking is not too hard. Go to the intake duct/snorkel from the air filter and you will see/feel a small ~3/8 hose coming off the back of it. Follow this hose... it should go directly to the rear valve cover. If it goes to the firewall or to the pipe bracket above the throttle body, it is routed incorrectly. Likewise, you will find one hose coming off a pipe at the firewall (right next to the fuel line); this hose should go directly to the pipe bracket right above the throttle body. For reference in your photo, the white hose is correct, the orange hose is the brake booster hose (correct), and to the right of the white hose drawing you will see a brass bracket with a hose pointing down... that is the one that should go to the firewall (the bracket slides in to the manifold right above the throttle).
More likely, assuming of course that the manifold and throttle body are tightened down evenly/tightly and the manifold was not cracked by accident etc, is going to be a problem with your EGR port on the back of the intake manifold (just below the area in your photo). A few different things happen here when people unfamiliar with this model try to take it apart:
1) They simply drop the EGR gasket on removal and don't realize there was one there (you can't see it, so if you aren't holding a hand under it to catch it you'd never notice)
2) More than one set of EGR bolts was loosened (again operating by feel only) and not properly retightened when the correct bolts were reached.
3) Incorrect bolts were removed/loosened (nearest the manifold instead of farthest) and were either left off or over tightened and cracked the manifold.
Of course the basics always still apply like Chris mentioned... check for vacuum leaks around the intake manifold to engine mounting area and manifold to throttle body area. You can use brake cleaner while it is running to spray around the sealing surfaces listening for the engine to reach indicating you found a leak.
Otherwise, go right to the EGR port on the back of the intake... You will find double flanges there... the first from the pipe (leading down to the head) there are two 12mm bolts horizontally situated... these are the ones you are supposed to remove during the process. Then flange then reduces to pipe then flares out to another flange that bolts to the intake again with 12mm bolts but in a rotated orientation from before.
First off, make sure all four 12mm bolts are there and snug. If they are, loosen the outer bolts (farthest from the intake, nearest the pipe) several turns and then feel underneath them for a loose piece of tin. You should feel the thin metal gasket moving easily there. If you do not, the gasket is missing. If you feel anything other than a thin piece of metal gasket floating in there, then an incorrect gasket was used (paper, metal composite, etc will all leak here).
If the gasket is in place, it is possible the manifold-side gasket was lost/damaged, that is far less likely though since it is so difficult to service the manifold by unbolting it there, people usually realize the error before getting that far and go to the correct side of the flange instead.
Again if the problem only surfaced after the plugs/coils were replaced, your only suspected areas are going to be the EGR pipe and gaskets or the manifold sealing areas (or manifold itself if broken in the process).