Hi All,
My daughter had my 2000 3.4 back at college in Kentucky. It had about 165k on it,
Someone stole the catalytic converter (clean cut and did not harm the 02 sensors...gee thanks). After much deliberation I decided to replace it with an aftermarket CAT. Installed cost was about $350.
About 5 months after the new Cat the CEL came on. I had her take it to Autozone for a reading....P420. They said that narrows it down to the Cat or the 02 sensors. They reset the light.
I read a ton about this on this site and other sites as well. I came to the conclusion that there was too many possibilities of the cause including no problem at all. But I wanted to make sure because I did not want her stuck AND I would be flying to KY to drive her back to our home state of Washington after graduation.
About 2 weeks later the light came back on.
I had her take it to a local independent shop and they read it. They said it is reading p420 "inefficient" CAT. I asked them about the sensors as 165k is alot of miles for the OEM sensors. They did an electrical check on the sensors and said they are working fine and they doubt the CAT is an issue because it was so new. I asked for an estimate on the sensors as I am thinking about replacing them for piece of mind.
They gave me an estimate (about $400 for both).But they said I am wasting my money. So I took their advice and did not replace them. They reset the CEL. The rig ran fine throughout this whole ordeal.
A few days later I flew back to KY for graduation....when I was there the light came back on. I ignored it and we took off on our 2700 mile trip. Yes I questioned my wisdom.
About 400 miles into the trip the CEL turned off !!! Weird. It never came back on the rest of the trip and still hasn't. Truck ran great.
I have a suspicion of why it fixed it self. I read somewhere that the CAT had to get hot enough for the rear sensor to reset properly. If that was not the fix maybe it was a better grade of gas through the fuel tank? I suspect my daughter was running 85 octane and I put 87 in it? One clue was the MPG on the first two tanks was we only got 16mpg. After that we got 20-22 loaded down and completely stock.
Weird but good conclusion. I hope that is the end of this saga.
My daughter had my 2000 3.4 back at college in Kentucky. It had about 165k on it,
Someone stole the catalytic converter (clean cut and did not harm the 02 sensors...gee thanks). After much deliberation I decided to replace it with an aftermarket CAT. Installed cost was about $350.
About 5 months after the new Cat the CEL came on. I had her take it to Autozone for a reading....P420. They said that narrows it down to the Cat or the 02 sensors. They reset the light.
I read a ton about this on this site and other sites as well. I came to the conclusion that there was too many possibilities of the cause including no problem at all. But I wanted to make sure because I did not want her stuck AND I would be flying to KY to drive her back to our home state of Washington after graduation.
About 2 weeks later the light came back on.
I had her take it to a local independent shop and they read it. They said it is reading p420 "inefficient" CAT. I asked them about the sensors as 165k is alot of miles for the OEM sensors. They did an electrical check on the sensors and said they are working fine and they doubt the CAT is an issue because it was so new. I asked for an estimate on the sensors as I am thinking about replacing them for piece of mind.
They gave me an estimate (about $400 for both).But they said I am wasting my money. So I took their advice and did not replace them. They reset the CEL. The rig ran fine throughout this whole ordeal.
A few days later I flew back to KY for graduation....when I was there the light came back on. I ignored it and we took off on our 2700 mile trip. Yes I questioned my wisdom.
About 400 miles into the trip the CEL turned off !!! Weird. It never came back on the rest of the trip and still hasn't. Truck ran great.
I have a suspicion of why it fixed it self. I read somewhere that the CAT had to get hot enough for the rear sensor to reset properly. If that was not the fix maybe it was a better grade of gas through the fuel tank? I suspect my daughter was running 85 octane and I put 87 in it? One clue was the MPG on the first two tanks was we only got 16mpg. After that we got 20-22 loaded down and completely stock.
Weird but good conclusion. I hope that is the end of this saga.
