Summary
If you own a vehicle with a third generation Prius powertrain, you’ll find many recommend you clean its exhaust gas recirculation (EGR) assembly. That takes a lot of time and effort. In reality, there’s a service bulletin to replace the assembly’s valve back in 2015. Despite what internet mechanics say, I found that completing that service bulletin was all that I needed.
Retrospecting
On my 2011 Lexus CT200h, I cleaned out the air intake manifold and EGR assembly (pipe, valve, cooler) as well as swapped out all the gaskets. Upon reassembly, I fond my console expressing the warning CHECK HYBRID SYSTEM.
The car could run, but would repeatedly rev and idle RPMs before eventually dying. So, already committed to the completing the project without professional help, I picked up an OBD2 reader (BlueDriver Pro) and read out the following codes.
P3190: Poor Engine Power, Confirmed CodeP3190: Poor Engine Power, Pending CodeP3190: Poor Engine Power, Permanent CodeElectronic-Controlled Power Steering Code
C1259: HV Control System Regenerative Malfunction CURRENT/HISTORYAntilock Brake System Code
C1259: HV Control System Regenerative Malfunction CURRENT/HISTORYElectronic-Controlled Power Steering Code
C1259: HV Control System Regenerative Malfunction CURRENT/HISTORYAntilock Brake System Code
C1259: HV Control System Regenerative Malfunction CURRENT/HISTORYEngine Codes
P0300: Random/Multiple Cylinder Misfire Detected CURRENT/HISTORYP0303: Cylinder 3 Misfire Detected CURRENT/HISTORYP0304: Cylinder 4 Misfire Detected CURRENT/HISTORYP3190: Poor Engine Power CURRENT/HISTORYRadar or Hybrid Control Codes
P0A0F: Engine Failed to Start CURRENT/HISTORYP3000: Battery Control System CURRENT/HISTORY
Doing some research, I found this previous post where the author describes a similar situation while reading out codes P0121, P0123, and P2135 (none of which I have). Another reader points out that these codes are “all related to the throttle body,” but I wasn’t so lucky. From these codes, it appears cylinders 3 and 4 are being choked with excess air exposure.
After disassembling and reassembling my work to check for loose connections and reseting the hybrid battery’s trunk-located safety plug, I acquiesced.
After I dropped the car off at the dealership, they called me to explain there is a service bulletin (POL16-02) to replace these EGR valves and they think it will solve my issue. This was in line with what we saw in the error codes; if the EGR valve was stuck open it would feed too much air into the cylinders.
In the end I could have skipped cleaning out the EGR pipe and cooler a la the many videos online and swapped out the EGR valve at the start.
This EGR valve retails for about $400. That service bulletin I mentioned has a part number for an EGR Valve Replacement Kit (Part No.: 04004-58137). It includes the valve and several gaskets for about $200. You can call a dealership’s part department to get it quicker than the online sources.
Personal Takeaways
Doin’ it yourself (DIY) always goes poorly until you’ve experienced completing the job thrice. Don’t let parsimony get the better of you—if the job is a one off skip the Red Green Show LARPing and find a professional you can work with.