My 1990 Le started throwing a check engine light about a week ago. I pulled the codes, and the O2 sensor is the culprit. I bought a sensor and a socket, and some penetrating oil, and tried to have a go at it. I'm a pretty large guy, now, 6'4" and 330lb, and I've got some upper body strength. I cranked and cranked on this thing and couldn't get it out. I even put a 2ft cheater bar on the end of my wrench, and all I succeeded in doing is making the metal groan, and flexing my socket extension.

So I gave up and took it to my mechanic. He spent 2-3 hours on it, tried impact wrenches, tried heating it with a torch until the manifold was cherry red, and could not crank the thing out. Apparently the previous owner didn't know what "anti-seize compound" is.

So basically now I'm stuck with a non-functioning O2 sensor. Here are my questions:

How hard is it going to be to pull the rear exhaust manifold on this car and replace it with a junkyard one? Is this the best course of action?

Thanks for the help, guys. I'm about to pull my hair out

I would agree...but I'd be tempted to try the hot/cold trick one more time. This time however, keep the manifold nice and hot, and cool the O2 sensor quickly. Some freeze spray or a cold, wet towel ONLY on the O2, then quickly try to remove it. (leave the socket in the freezer until you're ready, too ).

The cold will constrict or shrink the O2 to an extent. Not alot, but maybe enough to free it up.

Then off to the wrecker.

Thanks for the advice, guys .

I may end up either drilling it out or replacing the manifold eventually. Right now I'm hoping and praying that I can get it out using a bunch of PB Blaster and some grunt work. I found some honest to goodness PB Blaster today at Advance Auto, so I've been spraying and whacking the manifold and sensor every 3-4 hours. I'm going to do that all day Sunday and then try going at it Monday.

I'm planning on using a 1/2" drive 7/8" deep well socket. I have a 3/8" drive deep well socket, but it'* about half an inch too short, so I'm hoping I can find one slightly longer. Attach that to a 6" or 12" extension, and put my jack handle/lug wrench on the end of it, which is a 2.5' steel pole. I pray I can crank it loose, pulling the manifold on this thing looks like it'* going to be hell.

I did find a bunch of manifolds in nearby junkyards for anywhere from $35-50 each, so replacing it might not be too bad. The thing I worry about is the manifold bolts being just as bad as the oxygen sensor, and not having enough clearance to work in at the back of the engine.

continue soaking with penetrant. If that doesn't work put your socket in the freezer for an hour have your mechanic heat the manifold surrounding area cherry red while you put your frozen socket on. Let the cold socket sit on the sensor for 30 sec,Then try loosening. You could first try this by simply idling the car for 5 min. then install the frozen socket and try.

having a frozen socket helps how?..just wondering..does the metal contract or somthing?

ok if you heat the exhaust pipe up, that makes the metal expand [very slight, but enough to help] and when cold the metal contracts.. causing the exhaust to expand, and the sensor to contract, gives you quite a bit more space, considering the close tolerances.. and anything can help.. soad with penatrating oil as SSEBONNE4EVA stated.. that will help you just that much more.


-justin

I didn't :(

Whoever installed this sensor did NOT put any anti-sieze on it. I tried and tried, and succeeded in only rounding off the sensor. I took the car to my mechanic yesterday, he'* going to pull the manifold and replace the sensor for me. This sucks, I feel like I just admitted defeat

I'm going to hunt down the previous owner and make them eat the old sensor.

Your hammer (or wrench in this case i guess) wasn't big enough? lol....

Sometimes you can't do it on your own. Oxidization could be playing a part in this too.

Hehe, the hammer was plenty big. My dad and I together had 600 pounds of muscle pulling on a 3 foot breaker bar 1/2" drive socket. The problem was that the crappy O2 sensor socket I bought expanded and slipped and rounded off the sensor, so there was nothing to wrench on :(.

and that is why I buy craftsman.. mmm lifetime warranty for tools that don't break unless taken over their limits.. and they'll replace it free.. so its all good! I have found the "buy it cheap, buy it twice" saying always applies, no matter how many times I have tested it. The only thing I have of generic quality is a rotory tool [made by a company called grip??] and a grinder made by an unknown brand, due to know badging.. all in all they hold up well, except the grinding pad and the attatchments that came with the rotory tool.. but other than that, the 10$ I spend on the two [combined, not each] was well worth it.. except the $7 dollar socket set which broke on its first use changing a battery.. [comparable to a $40 one at sears].


-justin