Pre-Cat O2 Sensor Removal in 2001 - Toyota Nation Forum : Toyota Car and Truck Forums

teppista881 · 07-30-2009, 11:00 AM

Yesterday I was trying to take out the pre-cat oxygen sensor in my 2001 Prizm (3 speed Auto). I removed the two 12 mm nuts that hold down the sensor plate, but when I tried to slide the plate off the bolts, it was running into an obstruction that I couldn't see very well (it felt like a round pipe-like object--part of the exhaust manifold?). Is there a trick to getting the sensor out? Or do I need to take off more parts first?

And while I'm asking, is there a trick to getting the gray electrical connection to disconnect? I admit, I always have trouble getting these kinds of connections off and often need to use a flathead screwdriver to shimmy them off. This one is in an awkward spot, though, and I can't really see what connects to what.

I apologize if these are basic questions, but maybe they can help out other novices too.

Thank you very much in advance!

teppista881 · 07-30-2009, 11:20 AM

Here is a photo, if that helps you visualize it:

http://i838.photobucket.com/albums/z...1/100_1769.jpg

Thanks again.

huangxin · 07-30-2009, 04:23 PM

the plate is part of the sensor, so after removing the 2 nuts the sensor itself should come straight out. IIRC, nothing is in the way, just pull the sensor straight toward the driver's side.

the connector is a pretty simple once you get used to it (first time took me 10 minutes to get it off, now it's like 10 seconds). there's a button like thing on the connector from the sensor's wire. you should see it if you look from the passenger's side. press it while holding the two connector and wiggle them apart.

teppista881 · 07-30-2009, 09:59 PM

Thank you for your help. The pipe-looking object in my photo is definitely blocking the sensor from coming out. Someone on another board suggested it was part of the assembly that connects the exhaust manifold to the exhaust pipe. The spring ("pipe") had shifted into the way of the sensor. I'm going to try to jostle the exhaust pipe out of the way so that it clears the obstruction. Maybe that will work. I think you are correct that the sensor should just slide right out, but the operative word there is should!

I'll also give another try on the electrical connector.

Thanks again.