c didy

Thanks Laker, appreciated. That makes sense since the wiring won't be twisting as the O2 sensor comes out. I'll try to trace it back to the engine compartment.

christallon

Yup,

Cut the bolts off and replaced with new, and bought a new O2 sensor. I can now switch back and forth without dealing with sensor seize

Laker

before you start, remove the blower tube in the engine. It will give you much more room to work / feel around.

Jacke2c

Use a dremel and a cutoff wheel (about three) to cutoff the bolt heads. Takes about 30 minutes for 3... ten minutes each. O2 sensors shoul dbe replaced every so often (other sites say every 40-6,000 miles.) so buy a new one for your cat by-pass.

FVD bypass came with what looked like copper bolts... You will like it!

c didy

Funny, I searched but couldn't find any detailed threads on O2 sensor removal for 964s. It should be something a lot of folks have done. I like the idea of a second O2 sensor. Removing the blower tube is a good place to start, thx.

And cat converter removal isn't exactly rocket science but I don't see anywhere else where it's discussed well. How big are the replacement cat bolts? M8 30 mm or so?

Laker

perhaps one of the folks that sells Euro Cats / Cat bypasses can sell you just the hardware 'kit' that each one comes with, or if you are in a schmoozing mood, maybe just find out what bolts are used in the kit. IIRC the gasket must be replaced as well as it is for one-time-use only.

Here is an example from FabSpeed (no affiliation, just local to me)

Disclaimer: My car is a low mileage garage queen so I had no problem with any bolts (including the heat shield ones) A little spray of WD-40 on each bolt and nut the night before and they all came off like a prom dress

c didy

"they all came off like a prom dress ".

I always envied guys like you.

Laker

Oh yeah? Ask me about my dried out seals...... :-)