Hello, A few weeks ago I had to disconnect the battery to replace a headlight bulb. Shortly after, my Check Engine Light (CEL) came on and remained intermittently for about two weeks. Instead of visiting a mechanic, I purchased a ScanGauge II to read the fault code and attempt a DIY fix. I haven
Mohawkmtrs wrote: Your 2004 Acura RSX Type S uses Air/Fuel (A/F) sensors, not standard oxygen sensors. These are specialized sensors that provide air-fuel ratio feedback to the engine control module. Did you replace both the upstream and downstream sensors, or only the upstream one? I recommend removing the original upstream sensor and installing a genuine A/F sensor from the dealership for proper compatibility. I replaced both the upstream and downstream sensors. However, dealer-priced parts would cost over $700 — is there really no alternative to using an OEM A/F sensor? I appreciate your insight.
First, verify your wiring connections using a factory wiring diagram. Ensure all fuses (both under the dash and in the engine bay) are intact. If no signal is detected from the upstream sensor by the Powertrain Control Module (PCM), the issue may stem from improper installation or faulty splicing. If the hardware checks out, try replacing only the upstream A/F sensor — note that the downstream sensor remains a standard O2 sensor. This is a known fix for P0134 on 2004 Acura RSX Type S models. While not inexpensive, it's often the most reliable solution.
Your 2004 Acura RSX Type S uses Air/Fuel (A/F) sensors, not standard oxygen sensors. These are specialized sensors that provide air-fuel ratio feedback to the engine control module. Did you replace both the upstream and downstream sensors, or only the upstream one? I recommend removing the original upstream sensor and installing a genuine A/F sensor from the dealership for proper compatibility.