Removal of a rusted O2 flange from exhaust pipe

Tiny
JAB1234
  • MEMBER
  • 1998 TOYOTA TACOMA
  • 2.4L
  • 4 CYL
  • 2WD
  • MANUAL
  • 230,000 MILES
I have the upstream o2 sensor on my 1998 Tacoma, original exhaust system. The nuts on the bolts are rusted away except one that has a little of it left that I can remove with a wire brush. The thing is I took a hammer and chisel to set the o2 flange free from the exhaust. Not a movement at all(there are no nuts holding the it down). It seems that it has rusted onto the exhaust system over 18 years. The exhaust system is still good as it passed inspection lately. I don't want to pay a repair shop 150 dollars for a 15 minute job. What can I do to loosen/break free the flange?

2nd thought.I am in Virginia. Is there a way to not replace the o2 sensor. Have the truck run ok. And still be within DOT regulations? Thank you.
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Saturday, July 2nd, 2016 AT 6:14 AM

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Tiny
CJ MEDEVAC
  • EXPERT
The sensor is needed to keep the vehicle in closed loop (running efficiently) Usually open loop runs rich and not so good (but the idea is, the computer is keeping it running without needed data!)

Without it coming on line, the computer runs the vehicle on "preset values" set at the factory, instead of on "current" Fuel burns/ outside temps/ etc. Whereas it's using "real time" data to squeeze out the best burns that it can for best MPGs and performance.

(Unlike a 1946 and 1977 Jeep with a carburetor, That just make you look and feel good, draw in females, and just don't give you the pains of a modern vehicle!) (It's not too late!)

Lets try a (plumbing) Torch!

Heat the metal close to (1/2 inch or so) from the sensor, just do circles around it with the flame. This will expand the metal (and the female threads). The bigger the female threads get, the tightness on the O2 sensor male threads get looser. DO NOT HEAT THE O2 SENSOR! The cooler it is, the more contracted (smaller) it remains.

Pic below is "expanding" nuts on bolts or u-bolts to make them free up, trying to keep the bolts cooler.

This is a have the wrench ready and heat and try, heat and try. Continuing to Drag-Butt and not getting in there fast, will eventually get the Male parts hot, they will expend too, then you are not getting anywhere!

Always do this outside and with a fire extinguisher handy! No need in losing your vehicle and house in the same day!

Make sense?

The Medic
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Saturday, July 2nd, 2016 AT 7:20 AM
Tiny
GJGOGOL
  • MEMBER
How do you break the rusted flange loose from the pipe?
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Monday, August 29th, 2016 AT 10:05 PM
Tiny
RENEE
  • ADMIN
Use a torch like CJ has mentioned and when it is hot strike it with a hammer, this should help, double check to make sure all of the bolts have been removed, also undo any exhaust system hangers, this will put tension on the system which should help.
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Tuesday, August 30th, 2016 AT 9:08 AM

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