I am installed new HFC, and I am having a hard time taking off the sensor assembly off of the stock cat convertor. Are there any tips/ways to take it off? Also, what size wrench/hex should I be using? (7/8?)

Thanks.

 

See if AutoZone will loan you one of these. The slot in the side prevents cutting the wire.

 

I actually just came back from there and rented it. The damn sensor is just not budging. I sprayed it with some WD40, hoping it would loosen the threads, but nothing.

 

The catalytic converter is off the car right?

Try some penetrating spray (liquid wrench). Let it sit overnight.

Last effort. A torch to heat the sensor. Don’t burn up the wires.

 

what size does the 02 sensors take on a DE oem cat?

 

No, cats are still on the Z.
But I finally got pissed, and with some angry strength they came out.
Now, I am having a problem removing a bolt from the driver's oem cat (still on car).
It's the topmost bolt, it's directly in front of the steering column and literally impossible for me to reach and remove. I mean I can attach a driver to it, I just can't move the driver because there is no room!
Ah!

 

LOL. If the cat is off the car you can put it on the floor and stand on it to get some leverage.

 

You can remove the steering linkage buckle for more room. I do not advise this if you have VDC.

 

Don't laugh. I did the removal kinda backwards.
Took off the 2 bolts that go to the y-pipe. Then disconnected the 02 plug, removed the 02 sensor, then removed the 3 bolts that go into the header.

But this last bolt is taking it's toll on me. It's the last thing I need to do before I bolt up the new HFC's...arg.

 

i did mine on jack stands also... it was fun My 02 sensors came out fairly easy with the rented tool above thank god. The bolts were a ***** though. Dont worry partner, after you get the stockies off, its downhill from there. Bolting up the new cats will take half the time.

 

davidv where the hell was that suggestion when I was doing it!? those wouldve made life alot easier when I was under my car on ramps... I got frustrated to the point that I was going to tear the head shields off my cats lol. btw go ahead and get like 6 extensions...your gonna have to thread em through the engine bay to get the bolts loose at the top flange.

 

After much frustration and some help from my brother, I got that damn bolt out. And bolted up the new HFC's. Very relieved.
But now, there's a nice stench from my exhaust, a mix between WD40 and PB spray, oh yeah! I sprayed that crap everywhere to loosen up the bolts and most got in the y-pipe lol.

Yeah, I had to loosen/tighten the topmost bolt on the passenger side through the engine bay.

 

For me, I used: Wrench + Hammer. Took maybe one or two good hits and I knocked both O2 sensors loose. When you put them back on your HFC's, just use some anti-seize compound so that they are easier to remove when you take them back out.

Oh, and yes, PB Blaster is a god-send when you're removing the y-pipe. The bolts on mine were pretty much fused to the flanges. >_> Pb Blaster + Hammer took care of that though.

 

just put some elbow grease into it