Stuff you shouldn’t use impacts to remove? O2 sensors okay?
- Thread starter mikey03
- Start date
dcg9381
Well-known member
Anything that might sheer.. It's always a toss-up on an impact. Exhaust bolts/nuts/studs come to mind.
I'm gonna go with impact out of the gate on these, after soaking them for 24 hours. You can buy a specific socket so you don't have to clip the wire.
2ndGearRubber
Well-known member
Issue with an impact on an O2 is the shock can break the heater circuit inside. So if you're reusing it, I would advise trying that last.
Rusted Nut
Well-known member
O2 sensors come out of warm pipes with less chance of breaking the bung, than they do coming out of a cold pipe. Personally I wouldn’t use an impact on a sensor.
RPH
Well-known member
Left handed threads when unknown. Quickly on impact you realize the mistake!
If your not reusing it is okay? If your cutting the wires off to use a 6 point deep socket on it could that damage the bung threads compared to if you used a breaker bar with cheater pipe
2ndGearRubber
Well-known member
You can impact on the sensor socket. You'll strip the sensor with an impact more likely prior to damaging threads. Usually thread damage only occurs when the sensor is seized in the pipe or galls upon removal.
Bubba Fett
Well-known member
Oil plugs. Battery terminals. Anything interior. 
I'd just be surprised if you could access an O2/AFR sensor with an impact. Most of the time those sensors are difficult to access.
Having said that, never used an impact myself. I usually just go with a 22mm wrench, if that doesn't work opt for a sensor socket.
Having said that, never used an impact myself. I usually just go with a 22mm wrench, if that doesn't work opt for a sensor socket.
2ndGearRubber
Well-known member
My preference is almost universally a Wright grip 22mm. Usually you can't get the impact in, but sometimes the pipe is coming out anyways. If an impact is involved it's with a universal joint, extension, etc.
It's a really annoying variable because the front desk wants to sell at a price, but I'm not going to be contorting and fighting sensors "to see if they'll break free". Of course, nobody wants to sell a ticket with 4 OEM oxygen sensors on it either since that's like another grand.
I'd certainly give it a try if I had "exhausted" all my other options. I soak them for at least a few days in advance. Actually any exhaust work starts getting blasted when I start thinking about the project. If the penetrant doesn't work, some heat applied to the area is usually all it takes.
BlakeTheCarGuy
ALLIANCE MEMBER
I don’t think I’d attempt it on an oxygen sensor. There are some things I just won’t use an impact on. Drain plugs, spark plugs, 02 sensors, most things inside the car.
alfadan
Well-known member
Don't do what my neighbor's buddy did and cut the wire off right at the sensor, and THEN bring it over to use my impact, which wouldn't fit in the space!
BombShelter
Well-known member
I'm having bad luck with 1/4" auto nuts, I broke the casting on a Bosch Alternator with the tiny wire connection, somebody put that on too tight and there wasn't room for any leverage with a hand wrench to loosen it. I also broke the tiny nut on a BMW Battery Connection which should have been easy to loosen.
I'm snooty. If an O2 sensor doesn't come out with a breaker bar I'll replace that section of exhaust. Or even the whole thing.
I might try an impact on it after the exhaust is removed with total failure as the expected outcome while the new exhaust is enroute.
I might try an impact on it after the exhaust is removed with total failure as the expected outcome while the new exhaust is enroute.
Schurkey
Well-known member
It's totally situational. It also depends mostly on how angry you are. Sometimes the sudden impact will loosen a fastener with less damage than slowly-applied force, and sometimes...not.
Broken fasteners are just a fact of life; and sometimes a person might deliberately break a bolt rather than spend hours trying to nurse it out.
An impact wrench can absolutely be used, if you can get the tooling in to access it. What damage that causes--if any--is situational, as described above. Sometimes it works, sometimes it causes damage.
O2 sensors are sealed to the bung with a crush-washer, exactly like gasketed spark plugs. It is a TOTAL waste of time, money, effort, and enthusiasm to "soak" an O2 sensor, because if hot exhaust gas can't get OUT, no liquid lube can get in to do any good.
Might make a lovely stain on the concrete where it drips off, though.
If you loosen the sensor and then spray it with penetrating oil, the oil can get into the threads...but the hard work of getting it un-seized is already done so you don't really need the penetrant.
Yes. Those sockets with the slot in the side are GREAT for INSTALLING O2 sensors. The split on the side makes them weak, prone to slipping, which rounds-off the hex wrenching surface. But putting the sensor IN doesn't require a lot of torque.You can buy a specific socket so you don't have to clip the wire.
If the O2 sensor isn't seized, they may work OK for removal. I've had "some" success with them. The tough sensors will require a wrench that is not split on the side. I bought a Wright 4928 7/8 deep impact socket for O2 removal. The Wright brand socket is broached all the way down, there's room inside the socket for the body of the O2 sensor (but not the wires attached.) Most brands of impact sockets are only partially-broached, you'd have to bust off the ceramic body of the socket to make those work.
Given the difficulty of removing most O2 sensors (by the time I get to them, they've usually been neglected for years if not decades) I've never re-used a sensor. So ANYTHING that gets the sensor out without too much damage to the female threads in the exhaust (I have several styles of thread restoration tools one of which is usually needed; sometimes the female threads are so wrecked that the whole pipe or casting has to be scrapped.
Worst O2 sensor I ever removed came out of the left exhaust manifold of a Hemi Charger owned by a guy my wife worked with. The "shop" he took it to pushed the car outside when they couldn't get the sensor out. My 3/4" impact wouldn't spin it out--although the extension length and U-joint angle needed would have eaten a lot of torque. We ended up with a 24" 1/2" drive ratchet, a 30-inch-effective length cheater pipe, and two guys pushing on it through an 18 or 24 inch extension and U-joint. Once it popped free, it spun out with zero damage to the exhaust manifold threads. I was really surprised.
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