Sorry for blowing up the forum with questions, but Im looking to replace the o2 sensor. Are there differences between downstream and upstream sensors, or are they both the same/interchangable? I see some for sale online, and they state they are for both, but Im unsure. thnks!!!

 

Yes the same sensors for up and down stream.

 

Upon further review, it looks like the plugs are different.. one looks like a male plug connection and the other female?

 

Whatever you do...

DO NOT BY BOSCH O2'S.. unless you want constant problems with them!
Do not buy them from ebay also...
Purchase them at your local trusted auto parts...

Only buy AC Delco replacements!

 

Tkz for the tip, may I ask why?

 

Because they have a high failure rate.... there JUNK!!!!

So anything you do to your Monte Carlo...
Always replace any electrical parts with OEM original replacement parts!

 

Will do, but before I order, I noticed a plug difference with the upstream vs downstream. Looks like the downstream ( one i need) is a male connection, whereas the upstream is female, can anyone confirm this?

 

i agree with mr, dave. i got an upstream o2 when i first got ma car at 89k, couple weeks ago the thing made my whole car act real weird. i was mainly getting codes for the o2.but went on rockauto.com and got a ac delco replacement and all the problems went away

 

I could be mistaken, but I think the front and rear sensors are different - or at least AC Delco shows different part numbers for them:

Front: ACDelco 213-2873
Rear: ACDelco 213-1331

You may want to double check when you're at Rock Auto or wherever you decide to go.