Became a member of the club over the weekend. Took about 4 hours and I have a 4 post lift in my garage which helps. This is for a 1991 NSX and I purchased the Science of Speed O2 sensors.
To get to the rear sensor I removed the shielding on the exhaust and manifold to get more room. Also removed a transmission/suspension brace to get extra clearance. Did the usual soaking with PB Blaster and heat. A 7/8 O2 socket wrench would not work as it was too tall to get a 3/8" bar on. The offset O2 socket just opened up and I was worried about rounding the nut of the O2 sensor. I finally cut down the connector (part that clips to chassie - but did not want to destroy in case I was unsuccessful in getting sensor out) and slid a 22mm closed end wrench over it. Before I did this I heated the bung with a propane torch for about 7 - 10 minutes. Put the socket over and managed to get a cheater bar over one of the open ends of the other side of the wrench. Bang - finally let loose.
The front one was not as bad. Did not seem to have as much corrosion. Was a little tuff removing the manifold shielding but despite some nicked up hands was not that bad. You need to remove the shielding to get close to the O2 sensor nut. Again lots of penetrating oil and finally heat. I slid the open end of the 22mm wrench on the O2 sensor bolt, put the closed end in a large diameter cheater bar, made sure I was spot on and pulling in the right direction and came right off. The tall O2 sensor socket was again too tall and the offset one just opened up.
I read several accounts of how people have done this and they all seem to be different. The most important thing was to get enough heat into the manifold with the propane tourch. If I were to do this again I would heat for over 10 minutes as I think this helped the most.
Good luck,
Drew Altemara
To get to the rear sensor I removed the shielding on the exhaust and manifold to get more room. Also removed a transmission/suspension brace to get extra clearance. Did the usual soaking with PB Blaster and heat. A 7/8 O2 socket wrench would not work as it was too tall to get a 3/8" bar on. The offset O2 socket just opened up and I was worried about rounding the nut of the O2 sensor. I finally cut down the connector (part that clips to chassie - but did not want to destroy in case I was unsuccessful in getting sensor out) and slid a 22mm closed end wrench over it. Before I did this I heated the bung with a propane torch for about 7 - 10 minutes. Put the socket over and managed to get a cheater bar over one of the open ends of the other side of the wrench. Bang - finally let loose.
The front one was not as bad. Did not seem to have as much corrosion. Was a little tuff removing the manifold shielding but despite some nicked up hands was not that bad. You need to remove the shielding to get close to the O2 sensor nut. Again lots of penetrating oil and finally heat. I slid the open end of the 22mm wrench on the O2 sensor bolt, put the closed end in a large diameter cheater bar, made sure I was spot on and pulling in the right direction and came right off. The tall O2 sensor socket was again too tall and the offset one just opened up.
I read several accounts of how people have done this and they all seem to be different. The most important thing was to get enough heat into the manifold with the propane tourch. If I were to do this again I would heat for over 10 minutes as I think this helped the most.
Good luck,
Drew Altemara
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