partsrep
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While driving my V6 4Runner on a highway trip with about 123000 miles on the vehicle, my check engine light and VSC light came on. I brought it to the dealer the next day. The dealer charged me $110 to check the code. They tell me the code PO430 means my catalytic converter is not working to efficiency and needs to be replaced. They estimate the repair at $1200. I then research online to find out more information about this code. I find out O2 the sensors may be failing from age and if they are unable to deliver the correct information to the ECM, it is possible to get a PO430 or PO420 code.
I bring it back to the dealer and have them check the sensors. Then they tell me, "the good news is your sensors are OK, but you actually need two catalytic converters." Again, I thank them for their time and take my 4Runner. I stop and pick up some Seafoam additive.
When I got home I disconnected the battery to clear the codes and added a can of Seafoam to the gas tank with a full tank of gas. I then added Seafoam into a vacuum line per the instructions. After that my 4Runner ran like it was brand new and the mileage increased 2 mpg on the highway. I purchased my own scan tool to check codes and after about another 2000 miles my check engine light came back on. I had the scanner with me on a trip when the CEL came on so I checked the codes. PO430 again. This time I cleared the codes with the scan tool. Everything came back to normal except a system monitor for the catalytic converter. My first thought was the dealer was right and this is going to be expensive. The scanner indicated "catalyst monitor incomplete". Some scanners might indicate this as "not ready". I didn't get any codes but went through plenty of drive cycles which should have reset the catalyst monitor. After 1500 miles of the monitor not resetting, I had to do something to pass my states emissions test which is done by OBD-II to verify there aren't any codes pending and all monitors are working OK. I bought two post-cat heated O2 sensors, installed them, and drove the car 4 miles and had all monitors functioning properly. The next day I passed my state emissions and safety inspection at the same dealer that told me I needed two catalytic converters.
I am sharing this to help others with a similar situation to understand that in this situation, the code indicated the catalytic converter was not working up to efficiency. But in reality, it was the O2 sensors malfunctioning, making the ECM think the catalytic converters were bad. With new sensors the ECM now gets an accurate reading and all systems are OK. I paid less than $75 for each sensor and I bought Denso, direct replacement (same as OEM in a different box and I replaced both L&R post-cat) and it took about 30 minutes to replace them both. I saved over $2300 from the dealer estimate.
I bring it back to the dealer and have them check the sensors. Then they tell me, "the good news is your sensors are OK, but you actually need two catalytic converters." Again, I thank them for their time and take my 4Runner. I stop and pick up some Seafoam additive.
When I got home I disconnected the battery to clear the codes and added a can of Seafoam to the gas tank with a full tank of gas. I then added Seafoam into a vacuum line per the instructions. After that my 4Runner ran like it was brand new and the mileage increased 2 mpg on the highway. I purchased my own scan tool to check codes and after about another 2000 miles my check engine light came back on. I had the scanner with me on a trip when the CEL came on so I checked the codes. PO430 again. This time I cleared the codes with the scan tool. Everything came back to normal except a system monitor for the catalytic converter. My first thought was the dealer was right and this is going to be expensive. The scanner indicated "catalyst monitor incomplete". Some scanners might indicate this as "not ready". I didn't get any codes but went through plenty of drive cycles which should have reset the catalyst monitor. After 1500 miles of the monitor not resetting, I had to do something to pass my states emissions test which is done by OBD-II to verify there aren't any codes pending and all monitors are working OK. I bought two post-cat heated O2 sensors, installed them, and drove the car 4 miles and had all monitors functioning properly. The next day I passed my state emissions and safety inspection at the same dealer that told me I needed two catalytic converters.
I am sharing this to help others with a similar situation to understand that in this situation, the code indicated the catalytic converter was not working up to efficiency. But in reality, it was the O2 sensors malfunctioning, making the ECM think the catalytic converters were bad. With new sensors the ECM now gets an accurate reading and all systems are OK. I paid less than $75 for each sensor and I bought Denso, direct replacement (same as OEM in a different box and I replaced both L&R post-cat) and it took about 30 minutes to replace them both. I saved over $2300 from the dealer estimate.
