99 Ford F150 5.4L Engine PO430 Code: Cat Converter Sensor Issue Explained
The check engine light came on today, and the diagnostic scan revealed a PO430 code. The scanner showed that sensor 2 on bank 2 has the same voltage reading as sensor 1 on bank 1. I took the vehicle to a repair shop, which advised replacing the catalytic converter. However, I'm concerned because in a properly functioning system, the post-catalyst sensor (B2S2) should not mirror the pre-catalyst sensor (B2S1) readings. This mismatch may indicate a faulty oxygen sensor or a downstream issue with the exhaust system.
The post-cat sensor B2S2 should not mirror the pre-cat sensor B2S1 reading. If both sensors show identical voltages, this suggests a potential fault in the downstream oxygen sensor or a problem with the catalytic converter. Please confirm if there were any other diagnostic codes or symptoms such as poor fuel economy, rough idle, or reduced engine performance.