[WannaBe]

What exactly does the O2 sensor do and how hard is it to replace? Also, my engine temp keeps jumping around...it almost seems that when the car is on an incline the temp goes up but when it's on a decline it goes down. Any thoughts?

 

[jfrolang]

The O2 sensor measures the amount of oxygen remaining in the exhaust gases, thus measuring your air/fuel ratio.

Sounds like maybe a stuck thermostat?

 

[WannaBe]

If my O2 light is coming on does that mean i need to replace it or adjust the fuel/air ratio? It doesn't stay on full time or anything like that, but once it does come on it stays on until i turn the enigne off. but again, when i turn the engine back on it doesn't come back on right away if at all. it seems to be at higher speeds that it comes on...

 

[jfrolang]

If you're getting codes for an O2 sensor, you'll probably end up replacing the sensor. If you've got an O2 socket and some penetrating oil, they're fairly easy.

 

[WannaBe]

what does an O2 socket look like? because i am thinking that i don't....uh, oh!!! :dizzy:

 

[jfrolang]

O2 socket

You should be able to buy or rent one at Autozone.

If you can't get one, you could use a wrench, it's just more tedious that way. It's 22mm I think.

 

[downest]

A regular open ended wrench works fine.

 

[SETI20]

http://www.crxcommunity.com/viewtopic.php?t=6045

 

[ludesrv]

A regular open ended wrench works fine.

It does but can get tricky if you have AC, and a stock fan, things of that nature.

The socket is 5$, and cuts the time down by half. Well worth it in my opinion!

 

[drnknmnky13]

A regular open ended wrench works fine.

It does but can get tricky if you have AC, and a stock fan, things of that nature.

The socket is 5$, and cuts the time down by half. Well worth it in my opinion!

To take it off just cut the wire and use a regular socket. That's the hardest part.

 

[SETI20]

No, I agree. This is just a must-have specialty tool.
Just like a proper spark plug socket.

 

[jfrolang]

To take it off just cut the wire and use a regular socket. That's the hardest part.

That's fine for taking it off, but what about putting the new one on? You can't cut the wires then. I'm betting many of us don't have a deepwell 22mm socket laying around either... which means a trip to the store. Best to just use an O2 socket.

 

[dohcrxl]

To remove, snip the wire and use a 22mm 6 point socket for best bite on the sensor. I've found that the o2s socket sometimes rounds the hex. Be sure to hit the exposed threads with a penetrating lubricant first, start the car and let it run til the engine reaches normal operating temperatures. Then hit the threads again with the engine running. The heat will suck this new lube even deeper. Let run another couple minutes to heat the sensor back up, shut off engine, then attempt to remove. Trust this method, you don't want to know the wrath of a rounded oxygen sensor stuck in a header stuck in an engine bay.

To install new one, clean FEMALE threads with a small toothbrush sized wire brush, hit MALE threads with lube, tighten o2s to about 35 foot pounds.

Your erratic engine temperature problem seems most indicative of an improperly bled cooling system.

 

[WannaBe]

I replaced the o2 sensor (don't go to NAPA to get an o2 socket - $25!!!) and i also replaced the thermostat. how do i properly bleed the cooling system? start the car and put anti-freeze into the radiator until i wont' take any more; putting in a little at a time? or is there a more effective way?

Baldy

 

[downest]

A regular open ended wrench works fine.

It does but can get tricky if you have AC, and a stock fan, things of that nature.

The socket is 5$, and cuts the time down by half. Well worth it in my opinion!

I'm an idiot, I forgot they were in front on the stock manifold, mine is under/behind the motor.

 

[dohcrxl]

I replaced the o2 sensor (don't go to NAPA to get an o2 socket - $25!!!) and i also replaced the thermostat. how do i properly bleed the cooling system? start the car and put anti-freeze into the radiator until i wont' take any more; putting in a little at a time? or is there a more effective way?

Baldy

Fill the system with a 50/50 mix, idle the engine with the radiator cap open until the fan come on twice, all the while topping the radiator off as it sucks the coolant in to fill air pockets within the engine. After the fan comes on the second time, this should've been more than enough time to bleed/burp out the system. Top off and reinstall radiator cap. You're done.

 

[jimwww]

Also, my engine temp keeps jumping around...it almost seems that when the car is on an incline the temp goes up but when it's on a decline it goes down. Any thoughts?

I have the same problem in my crx.. my first thought is to replace the thermostat and coolant. If that does not work.. then I guess the radiator replacement is in order.