DTC P1134: Front Ho2S Micro-Computer Problem: Notes
WARNING: This page is about a different car, the 2002 Subaru Impreza. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
After replacement of faulty parts, conduct a Clear Memory Mode and Inspection Mode. See CLEARING DIAGNOSTIC TROUBLE CODES
under SELF-DIAGNOSTIC SYSTEM and INSPECTION MODE
under DRIVE CYCLES.