P2238 Heated Oxygen Sensor Current Control Circuit Low This code pops up every 100 miles or so. The problem started after an engine swap. Have replaced the AFR/O2 sensor twice, once with cheapo and once with Bosch. Replaced exhaust flange gasket to cat. Definitely getting signal from the sensor. Here are some charts. Thanks for any advice
Top chart is cruising on freeway, bottom chart is coasting to a stop. The values seem plausible to me. But I'm not an expert on heated O2s.
You've shown the output signal from the sensor, but the code appears to be about the control circuit for the sensor's heater.
That's helpful thanks. So maybe I check for voltage on the heater wires? And the heater should turn on at cold start?