Well kids it's that time again. Time for show and tell Stooge style. Todays show and tell is on how to remove the O2 sensors in our 348's. Now for me and some others it's a no brainer. But I'm writing this for the noobs that have no idea of where the O2 sensor is located, or how to remove it. I took me all of 15 minutes to remove the sensor. But then again I have done this before. For the new person doing this the first time I think you can have it off in around half an hour.
So where are the O2 sensors located? If you look down between the air box and the air inlet tubes you will see the O2 sensors sitting on the top of the catalytic converters. Image Unavailable, Please Login Image Unavailable, Please Login
The next thing we need to do is get the air box out of the way. I started by removing the inlet tubes from the air box. Image Unavailable, Please Login Image Unavailable, Please Login
Then you need to remove the air injection tube on the bottom front of the air box, just under the mass air flow sensors. Loosen the clamp that holds them in place, and then wiggle both of them off. Image Unavailable, Please Login Image Unavailable, Please Login
Next you will need to disconnect the mass air flow sensor from the air box. You can do this like I did by removing the little screws on either side of the mafs and leave them connected to the tubes running to the throttle bodies. Or You can loosen the claps holding them to the throttle body tubes and leave them connected to the air box. This time around I disconnected them from the air box. Image Unavailable, Please Login
Okay now remove the four 10mm nuts that hold the air box to the subframe, double check that everything is disconnected, and then remove the air box. Image Unavailable, Please Login Image Unavailable, Please Login
With the air box removed, you now have access to the O2 sensor connections. To remove the connectors all you have to do is press down on the clip that is on the top of the connector, then pull it out. Image Unavailable, Please Login Image Unavailable, Please Login
Next you will need to unscrew the O2 sensor. Since I didn't have a fanchy-schmancy O2 sensor socket I need to get a open end wrench on it. SO what I did was get the rear of the car in the air and removed the wheel. Notice my trick jack stand made from the finest American fire wood. Safety first . Once the wheel is off, and out of the way, you have a pretty straight shot to the O2 sensor in between the top and bottom a-arms. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Reach in between the a-arms, get your wrench on the the O2 sensor, and then loosen it. Since I didn't have the special O2 sensor socket, nor a 20mm open end wrench, I used a 7/8 wrench that did the job just fine. The O2 sensors shouldn't be put on gorilla tight, just snugged on. Once it is loose you can unscrew it by hand. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
The original Bosch part number for the O2 sensors is, 0 258 003 103. But when I looked up the sensor it was superseded by part number 0 258 003 222. I also found out that a Volvo 850 uses the same O2 sensors. I got the plug and play version. I didn't feel like fooling around with splicing wires. That and the price wasn't bad, $125 each. Image Unavailable, Please Login Image Unavailable, Please Login
Here is the new O2 sensor installed in it's new home. Remember it just needs to be on nice and snug. So don't try to set a world record for tightness. Oh yeah! The other thing was that the new sensors came with anti-seize already applied to the threads. That was a nice surprise. Image Unavailable, Please Login
And that boys is how you remove the O2 sensors on a 348, Stooge style. Happy wrenching. Image Unavailable, Please Login
Nice write up... Is that "trick jack stand" avaialble for purchase, or might you have the Ferrari part number? LOL.... Best, David
I didn't bother with the wheel well removal and simply went in from the top. With a proper O2 socket + long extension + swivel head, I didn't need to remove anything except the airbox (to reach the harness connectors where the sensors get plugged in). Total replacement time for both sensors was about 30 minutes. Mine we're frozen pretty tight, so a bit of PB Blaster was quite useful. The one thing about these O2 sockets, is that if you're not careful the O2 wiring can get bunched up or crimped. So just take a little extra care/time and it'll be fine. Image Unavailable, Please Login
Love it! *I would have mailed you my $15 O2 socket to have saved ya the trouble of yanking off the wheels, though! Just ask!
As usual Ernie.............this is an excellent write-up and worth its weight in gold to someone who has never replaced their O2 sensors!!! GOTTA LOVE THE BROTHERHOOD!!!
Luca is a budding young Ferrari Mechanic if I ever did see one!! Perhaps Luca and GG should get into the Ferrari repairing busniess?
Shemp my man you are CORRECT! And, I don't have a 22mm wrench either, so still would have had to used the 7/8. LOL!
They are available for purchase from your local hardware/grocery store. $7 for a pack of about 6-7 fire logs/jackstands. The great thing about them is, once your done you can use them for toasting marshmallows. HAHAHAAA!!! I have proper jackstands, but I didn't feel like lifting the rear end that high.
