Rudey08

Hey 944 folks, long time listener first time caller..

Hoping someone has found a solution to this problem and can tell me where to find the equipment needed to fix..

Ive battled a stubborn o2 sensor for the past few days. Ive thrown all of the tricks at it, soaking it multiple times w liquid wrench, butane torching the bung etc. I finally removed the section and attacked it with a pipe wrench. Its out, but of course, the threads are chewed to hell. I'm heartbroken.

Can someone tell me if chasing what threads are left with a thread cutting tool is realistic, and if so how to determine the size i need / where to find one? Or is something i need to find a machine shop for?

Thanks

V2Rocket

should be an M18x1.5 thread
you could probably find a thread insert or weld a new bung on next to the original one.

thomasmryan

Bummer....Pitch the sensor and chase the threads on the exhaust. Should be an 18x1.5 spark plug chaser.

The bosch equivalent part number is about 85.

PB, Kroil or wurths 'rost off' work well plus it helps if the exhaust is on the cool down temperature swing when it is time to crack 20 years of crust.

If the new sensor won't tighten, weld a new bung to the pipe if you know someone with stainless skills.

FRporscheman

That sucks. Like others have said, I'd start by chasing the threads and seeing if the o2 sensor threads in OK. If not, I'd have the bung replaced at a muffler shop, shouldn't be a big deal.

Actually, if you don't have a thread chaser and are about to buy one, I might just go straight for the new bung at the muffler shop.

KevinGross

Try to use a true thread chaser rather than a tap. The chaser will shape metal, remove debris, where the tap's job is to cut metal, which you don't want. This will be a lot easier with the exhaust off the car, and it'll need to be off the car if it comes to welding a new bung.

odonnell

http://www.summitracing.com/parts/sum-g2990/overview/

Just have an exhaust shop weld in a new bung, probably less hassle.

Rudey08

Thanks for the input everyone. So from the replies it sounded like this was where i tap out and leave it to professionals.

At lunch i took it to a small British car IRF that used what i imagine was a thread chaser ( he said it removes material from between the threads in cases like this) and worked it over for about 20 minutes. Those pipes are made of some tough metal!





Major thanks to Dave at Winged Wheel Garage in Pensacola FL, for dropping what he was doing and putting a strange new customers funked-up Porsche mid pipe on his work bench without a second thought!

FRporscheman

It's always nice to receive good service. Glad you got it solved.

fasteddie313

I have a helicoil O2 sensor bung repair kit... Too late..