02 Sensor Replacement?

[Nick12684]

Ok. My brother is away in the military, and im trying to get his car ready for him when he returns. we do not live in the same house. (lived with his mother) so i don't know his driving habits, and no one in the house hold seems to know whats going on either. He has a 2001 Camry 2.2L 4 cyl. It has a check engine light on so i took it to autozone and the guy told me it was a upstream 02 sensor issue. Well.. also. the exhaust flex connector (bradied exhaust tube that hooks the header pipe to the rest of the exhaust.) is done. leaking so bad that there is barley any exhaust coming from the tailpipe. these 2 problems, and me being fairly fimilar with cars. (just not having access to helpful info) im almost conviced that the 02 sensor is NOT bad. despite what autozone told me. at $150 im recultant to buy one and have it not fix the problem (turn of check engine light) i dont have a schematic of the sensor, its connectors or its wires. but we have 2 black wires, a blue and a white. I used my multimeter, i managed to figure out 1 black wire was the B+ the other 3 were....? (so its a H02S) so first are these prone to fail? 2nd how can i check to verify the sensor is good...or bad using a multimeter? 3rd. because of the huge upstream exhaust leak (before the CAT) could the fact that 1 is seeing 02 levels straight from the engine? and the other seeing near atmosphere 02 levels? or even 4th could it be something completely something unrelated. like a MAF or PCM? any light shead on this subject could help alot. thanks.

[ASG14]

My flex pipe on my V6 broke a few weeks ago, and set the CEL off for the O2. The O2 sensor should be fine once the flex pipe is fixed. Mechanic at my dealer that I know said it;s normal. What will happen is when you take your foot off the gas, it will suck in oxygen causing a major misreading. He even said it would likely be fine once the exhaust is fixed (which I plan to do next week).

[projektvertx]

Originally Posted by ASG14

My flex pipe on my V6 broke a few weeks ago, and set the CEL off for the O2. The O2 sensor should be fine once the flex pipe is fixed. Mechanic at my dealer that I know said it;s normal. What will happen is when you take your foot off the gas, it will suck in oxygen causing a major misreading. He even said it would likely be fine once the exhaust is fixed (which I plan to do next week).

That sounds about right. My flew pipe got damaged by a hard ice chunk way back in the stone age when I lived in Montreal and I had an identical issue occur. As soon as the flex pipe got replaced that week, the light disappeared.