I need to replace my exhaust manifold due to the dreaded cracking issue. My problem is I can't for the life of me get the lower after cat O2 sensor out. I have the slotted socket and I have sprayed penetrating oil and tried everything to get it out. It won't budge. The top one came out pretty easily with penetrating oil. Are there any ticks to getting it out. I don't want to have to drop another $100 if I don't need to. Thanks in advance!!!

 

Heat up the area around it. The metal with expand and make it much easier to get out. Just start up the car and let it run until the exhaust heats up. Then take it out and your golden.

 

Be careful using that method though, the exhaust gets very hot, very fast. I would suggest only letting the car run for about 30 seconds or so. Wear a long sleeve shirt and gloves if you have them

 

3/8" drive - little cheater bar helps.

 

"PB blaster" foun at ur local kragen

 

You have to be careful when using cheater bars since you won't realize how much force you are putting on the bolt/sensor and you could end up breaking it. I've done it many a time.

 

That o2 sensor doesnt cost $100 does it? Personally if i couldnt get it out at all i would just take my happy *** down to the local auto parts store get myself a new one to go with my new exhaust manifold and there you go. All new stuff. Most places recommend replacing your O2 sensors anyways for better gas mileage. They do get worn out too.