Embraer Undifferentiated or Other Model
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
ATC Issue All Types; Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter Wake Vortex Encounter
Air Traffic Control Issued New Clearance
Aircraft; Weather; Environment - Non Weather Related
I was flying pilot on ILS 8R at IAH. LOC was very squirrelly. Autopilot was chasing it; so I disconnected and hand flew probably around REIGN. LOC was very sensitive and fluctuating back and forth 1/4 to 1/2 dot. Kept it relatively centered. Was barely deflected; less than 1/4 dot and Tower override says we are south of localizer; turn left immediately and re-intercept.  According to CDI we were just slightly right; almost touching centered.  I made a correction to the north and changed to magenta needles to follow until outside of OM. While on magenta needles; we encountered wake turbulence. Aircraft in front of us was about 6 miles ahead. We had aircraft to the south on parallel below us. Went back to green needles outside of OM. Light rain but we got visual of the runway. Localizer seemed to be slightly off; and sensitive. I queried if anyone else had issues with localizer; Tower said no; and that we were back and forth across course for most of the arrival.  I wrote it up when we arrived at the gate. Threat of possible inaccurate CDI/localizer. Hand flying. Being south of localizer during parallel approaches is undesirable. Wake turbulence possibly because of south of course. Use magenta needles for longer on approach. Turn autopilot back on.
EMB Captain reported Tower advised of a track deviation on ILS approach to IAH.