Do I remove stock o2 sensor after installing lc-1?
 

Hey guys I just have a quick question and it's probably a major noob question. This is on a 90 miata with a t3 Garrett using eBay manifold and down pipe. (Flame away.) But do I keep the stock o2 sensor as well as adding a bung for the lc-1? Currently not using engine management, ms3 will be the next purchase. Just trying to get the turbo and everything on first but I am wondering if I'm supposed to keep the stock o2 sensor as well as the lc-1 wideband sensor? I already have one bung welded on the dp so just wondering if I need to drill another

Leave it in or you will throw a code. Remove ( it unscrews) after installing MS. Plug the hole. Many places sell the plugs.

The LC-1 has two analog outputs. You can program one of them to act like a narrowband O2 sensor and wire into your factory ECU. When you install the MS3 you can reprogram that output to provide all the wideband glory.

The second output goes to the dash gauge, obviously...