Lower or upper oring?
Lower can be purchased from Toyota.
Upper maybe sourced from local hardware stores.
How many miles do you have on the injectors. If they have been used for sometime consider sending them to rc for cleaning. They will replace orings, pintle caps and the internal filter. They also blueprint the injects before and after.
My stock ones with 40k were decent but one was 30 ccs under. They only replaced the filter as they were toyo injectors.
07 Exige S - PhB., TP, TP, LSD, Gotham, 2Bular Revised Header, 2Bular De-Cat, 2Bular 8x24 Burnt GT3, Cup Car Intake, 6k HID's, Schroth 4pt ASM Harnesses, Milled Steering Arms, Bronze Volk TE37, Carbon Craftsquare Mirrors, Reverie 5 Element Diffuser, Reverie Exige Race Front Spoiler, APR Canards, IMRP Side Skirts, Blackwatch Studs w/ Project Kics K40 Lugs, DBA 5000 Rotors, Goodridge lines, Sparco Wheel w/ Works Bell Quick Release.