Understand. I chose the 3 ton only because I work on more than my accord. I'd rather have it and not need it than need it and not have it.

 

I use 1 of those for both Accords I have here, along with my son's Civics. I've even used it on my daughter in laws 08 Pilot. If you're only lifting a corner, it's not a problem. It's not like you're trying to lift the entire vehicle off the ground.

 

Guys, thanks for all the hints. I finally ended up buying the 1.5 ton jack from Harbor Freight. It is light and more maneuverable. One issue I'm running into is that the higher one lifts, the more of an effort that's required to pump it up.

I drove the car around so that it reached normal operating temperature. I had a go with the heat shield bolts with a longer handle wrench. With greater torque available, one of the bolts still didn't come loose but that corner broke off. At the other corner I was able to loosen the bolt. The corner was fragile and twisted somewhat as I applied force. The net result was that the bolt came off but has now gotten lodged twisted in the socket and won't come off. In any case, with two corners loose, I was able to pry apart the heat shield on the side facing me and be able to snugly position the special offset/slotted socket. I applied more PB Blaster now that I was able to better see the location where the sensor was screwed in. However, I was still unable to remove the sensor. I also tried a long arm breaker bar with one difficulty being that it could only be positioned at certain angles due to the cramped work space.

My intent is to try it one more time on a different day. Hopefully the PB Blaster will get time to soak in. I may also have to raise the car higher and take the jack stand up one more notch. I have 2 questions. Since I may not be able to do it all at one time, can I drive around without the heat shield if I don't park on the grass? Second, can I drive around with the sensor disconnected? If the sensor doesn't unscrew on the next attempt, I may well have to use Seanjordan's solution of cutting off the sensor wires and applying a torch to the sensor threads. With the wires cut, I don't have to use the offset/slotted socket and be able to use a regular 22 mm socket which will allow greater torque to be exerted.

 

You can drive around without the heat-shield and with the wires cut. You may get a CEL for the sensor, but the new sensor will clear that code (or clear it later with your scanner).

 

Yup. On my wife's Accord, I used screw type hose clamps to hold the heat shield back in place, as the corners with the screws had rusted off. I did this mainly to stop the rattle of the shield.

 

I took the ultimate step of cutting off the sensor wires. In addition I removed another "shield" (I don't know what its called) which sits above the catalytic converter and houses the sensor cable that runs from the sensor to the bottom of the passenger seat. I also applied a torch to the sensor threads. The sensor did not budge when using the closed end of a combination wrench with a long handle. Repeated hammer blows to the end of the handle also couldn't work it loose. Prior to each attempt I applied the torch. I had also bought a 22 mm socket. It couldn't be placed on the nut as it was not deep enough. I can get a deep socket but then I may not have enough clearance to attach it a ratcheting wrench handle. Similarly it is unlikely that an impact wrench will have enough clearance. Anything else I can try?

 

How are you trying to do it. I know when I have seized O2s I lay on the ground and I use my body weight to pull down on it. You pull and it will pull you up then slam your body down and it always brakes. Your knuckles should be almost at touching the bottom of the car. This is the method I use when I am on jack stands. A lift is a lot easier so no need. You should be using at least a 1/2 wrench and a cheater bar to get more torque. I have used an impact with an extension before using a pivot socket to help break it loose some.

 

What are you using for a torch? You should use an oxy torch as the cat convertor generates quite a bit of heat, and a regular propane torch might not get it hot enough. You could try one of those turbo torches too, and just hold the heat closer to the convertor in a single spot to get it to glow red/orange first.

 

Toecutter, from what I understand, the oxy torch is normally used for welding and metal cutting purposes. I'm reluctant to invest in the equipment and am afraid of warping the sensor and cat metal junction due to the intense heat.

Seanjordan, thanks for the vivid description of the mechanics and I can visualize exactly what you're saying. I bought a 22 mm deep 1/2 inch drive socket this morning. After removing the 2 shields, much to my surprise, the socket did fit with room to also attach a 1/2 inch drive breaker bar. However, try hard as I might, the sensor nut didn't budge. I'm limited by how high the floor jack can take me and the maneuverability of the breaker bar in tight spaces. I was going to try using an impact driver. The impact drive is 3/8" and the socket is 1/2" drive. I'll get a 3/8 to 1/2 drive adapter. That will be my last attempt.

 

With the torch, you want to heat the converter not the sensor.

And I'd be very careful about supporting the car properly if you're going to be underneath it pulling real hard on a wrench. Try to arrange things so you lift on the wrench. Then use a stack of bricks as a pivot for a long crowbar, so you can be out from underneath the car just in case it decides to fall.