Muffler shop caused cel

Muffler shop welded my leak i had on my down pipe the y pipe after the exhaust manifold on my 97 tacoma 4banger well now i have a cel. I did notice the worker welded and had a flame on the exhaust y pipe with the o2 sensor on it, possibility he fried it? I erased and it came back

 

ima try to clean the o2 sensor

 

Have you checked what code(s) it's setting?

O2 sensors can handle very high temperatures (they have to since they live on the exhaust pipe) so unless they damaged the wiring or had their ground clamp on it while welding I doubt the sensor was damaged from that.

 

Truck has been running fine, these appeared after

 

Possibly just a fuse with heater circuit, but also very common for old sensors to break the heater circuit when disturbed.

Check fuses first, doesnt hurt. Likely the sensor internal circuit. Cleaning it wont help.

 

so check the fuses, okay ill do that after I get out the gym, you know if its under steering wheel or under hood?

 

Should be under the hood, might be called a heater fuse, HTR fuse, but checking all fuses doesnt hurt. A test light with the key on makes it super quick.

 

Cool thanks. Test light? never heard will look into it

 

The fuse can't be blown, the O2 heaters are powered by the EFI fuse which also powers the fuel pump among other things. Therefore the truck wouldn't even run if it was blown.

You can unplug the sensor and check the resistance of the heater circuit to see if it's open or not.

 

Some models have separate heater circuits, but I was too lazy to check this one haha. I'm getting lazy with my advice.

 

Yea the older trucks tended to have most of the EFI components on 1 fuse, newer ones have less important components fused separately.

 

wheres the heater curcuit? sorry idk

 

You have to unplug the sensor and check across the terminals shown with a meter set to ohms.