I just inserted my d16a6 into my 88 hf chassis and tried to get the old 02 sensor off my hf header...its on there and i can't get it to budge...a new unit costs $240 from the dealer!!!...so i heard you can heat them up with a torch to help break them loose...i just got done talking to my local mechanic and he said once you use a torch on an 02 sensor it will no longer work...is this true or is there a certain method you need to do to get it off?

also what happens when you run the car without the o2 sensor?...does it run in limp mode?

 

I had the same problem, spray WD40 around the top of the threads. You may have to do it a couple of times. That should help you loosen the sensor enough to take if off. I had to take a hammer to a wrench to loosen mine, it still works, but you risk damaging it. Good luck

 

heating it could damage it . but what will probally happen is you will strip the threads off of it if you do break it loose. try some oil but be careful not to get it on the sensor (the part that goes inside the pipe) itself or it will not work.