o2 Sensor Issue

[TedS03]

2003 Tundra 4.7 motor 72,000miles. Check engine light came on, catalytic converter was the problem. installed an after market converter, drove it for approximately 500 miles when the check engine light returned, this time it was the o2 sensor on the discharge side of the recently installed converter. OK, not uncommon the failed converter caused the sensor to go. Replaced the o2 sensor and drove it 20 miles and the light has returned with the same fault code telling me the same sensor has failed. Is it possible that an after market converter would cause the problem or do I actually have a new faulty o2 sensor ? Any input would be appreciated. Thanks

[NightRodeo]

Some times if an o2 sensor goes, the o2 sensor fuse will go out also and that can cause the check engine light to come back on. Places like auto zone will only show the o2 sensor as bad on there tester. It wont pick up the fuse being bad or out. Usually a dealership or a reputable mechanic shop can check with a real diagnostic computer to see if the fuse is what is bad. Some times the o2 sensor can be faulty even when new. If you know some one that can check with a real diagnostic computer and not charge you or not charge you a lot they can tell you for sure what the problem is.

[TedS03]

Where is the fuse located ?

[NightRodeo]

It is usually located in the fuse box under the hood

[TedS03]

I did not realise there was a fuse for the sensor. I will check into this a let you know how i faired. Seems like it could be a simple fix. Thanks for your help.

[TedS03]

All the fuses tested fine. When I started the truck up the check engine light never came on (and I did not reset it either). I used it to do some running and it never came back on. I don't know what to think.
Thanks for your help NightRodeo.

[NightRodeo]

Your welcome. Some times the check engine light can be weird like that. It may have just needed some time to reset. It can be hard to determine some times.