Citadel: Reaper Code Fragments
During the Rannoch: Geth Fighter Squadrons mission, look out for the strand of code that’s separate from all the rest. After destroying it, you can take the fragments back to the Asari War Strategist near the entrance to the Embassies for 30 XP, 1,000 Credits and an updated War Asset - Asari Second Fleet .
Citadel: Cerberus Automated Turret Schematic
During the Tuchanka: Bomb side mission, if you collect the Turret Schematics from the terminal that’s located in the room just before you slide down the ladder and make your final stand, take them to the C-Sec officer overlooking the Presidium Commons for your reward.
Athena Nebula: Hesperia-Period Statue
The solar system known as Vernio is hiding this secret on the Saturn lookalike planet known as Polissa . Scan the planet and then take it back to the Asari sitting on the seat in Presidium Commons for your reward of +5 Reputation points, 15,000 Credits and improvements to your war assets.
Citadel: Wounded Batarian
Head down to the refugee camp in the Citadel and in the first set of containers on the right there’s a highlight for a Nurse. Approach him to chat to the Batarian; once here you can decide to pull the plug on his life-support or let him live. Your decision will net you +5 Reputation, 210 XP and 5,000 Credits .
Citadel: Target Jamming Technology
During the mission Rannoch: Admiral Koris, when the door opens leading either to or from the left-hand AA gun emplacement, to the right of the door on a terminal you’ll find the Turret Schematics . Take it back to the Turian in the Presidium Commons, near the bar area for 30 XP, 1,000 Credits and improvements to War Assets - Citadel Defence Force .
Citadel: Batarian Codes
WARNING! If you don’t complete all of this side-mission straightaway (i.e. go off and do something else mid-mission) then it will glitch and you can no longer complete it!
Activate this side-mission by heading to the Spectre computer and accepting the enabling from the e-mail menu. From here, head to the medical bay and the first lab on your right (past the reception area) has a console you can access. Now head down to the Docking Bay and find the terminal to the left of where you originally met Diana Allers.
After you activate this one, head to the far end of the refugee camp; this is where a certain Batarian (who Mass Effect fans will know) appears. If your Paragon skills are high enough, you can persuade him to join your war efforts, otherwise you’ll be forced to kill him. Persuading him to offer his fleet will reward you with +7 Paragon Points (or Renegade if you killed him), 210 XP and a new War Asset - Batarian Fleet .
Citadel: Cerberus Turian Poison
Speak with the Salarian doctor in the Citadel medical bay (in the room opposite where your colleague was recovering before). During the Ex-Cerberus Scientists mission, when you first head upstairs to the control room, the poison can be located near the top of the stairs. Bring it back to the doctor for an improved war asset and reputation points.
Citadel: Cerberus Retribution
At the Presidium Commons, look for the couple standing halfway up the stairs beside the C-Sec station. You can overhear their conversation - if you then immediately go back to the C-Sec office, confront the would-be assassin sitting on the sofa to your left. You can persuade him out of doing it if your Paragon points are high enough.
Nimbus Cluster: Library of Asha
Head to the Nimbus Cluster , enter the Agaiou solar system and scan the planet Carcosa for the artifact. Bring it to the Asari standing on the second floor of the Purgatory Bar near the stairs for 15,000 Credits, +5 Reputation points and an updated War Asset - Asari Sixth Fleet .