is that the one that is found on the "u - bend"?

 

No, that's bank 2.

 

As Chibi said, the one in the U bend is bank2.

From under the hood, look on the back of the engine, loog for the rear exhaust manifold and follow it, before it connects to the downpipe (the pipe that leads the exhaust under the car), you will see a sensor in the manifold. That's the upsteam Bank1 sensor.

 

Here's a good view of the exhaust outside the engine.

 

lol wow!thats very visual!and made me understand 100% so i think i will be replacing it because the car has 132000 but the engine is rebuilt.but everything else has those amount of miles so i need to freshen up the monte a bit lol.thanks guys

zzp sells these sensors right?

 

02montess, don't worry about stealing the thread. It's all good. I'm all about learning as much as I can.

Maniac, I thought about getting a new head, but my Dad is a machinist and he says he can fix it. He's coming out on Saturday to give it a shot.

 

Here are the pictures of the mess I found under my valve cover.

 

@02montecSS - From my understanding of O2 Sensors on mid 90's to current GM cars, stick with AC Delco or Delphi sensors! Yes, it's true, other brands (such as BOSCH) will work on these cars, but there are two big problems. First, the car may not be properly calibrated for the readings from off brands (meaning you don't get the most optimized performance/MPG from an off brand). The second problem, people have reported higher odds of getting O2 related engine codes from an off brand. Not a guarentee, but possible. A guy I refer to as my GM Guru (can diagnose problems when i hit a wall) said he only uses AC Delco or Delphi O2 sensors in GMs.

@mairj40 - I hope your dad can get things properly repaired on that head. That looks like an AWEFUL mess and I would have NEVER thought about something like that happening. Keep us updated! Keeping fingers crossed that your dad succeeds and puts an end to this mystery problem!!

 

Well, the car is fixed... finally. My Dad came out today and re-drilled the holes and installed loc-tited helicoils. He even staked them at the top, so they should stay in this time. I put new plugs in it and it is purring like a kitten.

 

Awesome news! I've only used a helicoil once (on my current '94 Grand Am, spark plug hole). I hope it holds up for your application. If not, you're way ahead of the game KNOWING where to look.

Here's to LOTS of happy miles now!!