HC Adsorption Catalyst Efficiency Below Threshold Bank 1
Table of contents
P2423 TOYOTA Possible Causes
- Faulty Hydrocarbon Absorptive Catalyst (HCAC)
- Exhaust tube
- Intake air leaks
- Faulty Fuel injector
- Fuel injector leaks
- Faulty Spark plug
- Improper ignition timing
How do I fix code P2423 TOYOTA?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Cost of diagnosing the P2423 TOYOTA code
The cost of diagnosing the P2423 TOYOTA code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P2423 TOYOTA Description
Hydrocarbon Absorptive Catalyst (HCAC) system consists of the Three-way Catalyst (TWC) and two heated oxygen sensors. The TWC has a character of absorbing hydrocarbons (HC) emitted soon after the engine start. The two heated oxygen sensors, sensor 2 and sensor 3, are used to detect deterioration in the TWC. The HCAC system is installed in the lower part of the exhaust system, after the front catalyst.
The ceramic portion of this catalyst is coated with the HC adsorbent* material. The TWC material is coated on top of the HC adsorption layer.
While “active air-fuel ratio control” for detecting the front catalyst deterioration is performed, the Engine Control Module (ECM) determines if the rear catalyst has deteriorated as well.
The ECM compares the waveforms of the heated oxygen sensors located before and after the rear catalyst to determine if the catalyst capacity has deteriorated.
If the catalyst is functioning normally, the waveform of the heated oxygen sensor 3 indicates RICH and LEAN alternation more slowly than the waveform of the heated oxygen sensor 2 located before the catalyst. If both waveform variation rates are similar, indicates that the catalyst capacity has deteriorated.