My guess is that whatever is causing the gauge to read zero, (assuming we still have normal
oil pressure) is also causing the check engine light to come on, and also will place a OBD code in the computer. These computers are great for helping diagnose problems, but they are only as smart as the info that is fed into them.
Go to the source.... check the pressure first with a good gauge. If you start driving it around to shops to have the codes pulled, you "could" be doing additional damage to the engine.
- Jim -