My CEL came on, and after paying the dealer $90 for a diagnosis, the diagnosis said:
103838 OPEN CIRCUIT 1.0 DRB TEST AND CHECK SYSTEM DOWNSTREAM O2 SENSOR

Well, first, how many O2 sensors does this car have. Second, where is the downstream O2 sensor located? I see one in the front by the oil filter, and another in the back of the engine. Feeling up and down the exhaust reveals no other sensor. Went in to same dealer today, and "service advisor" (another name for someone who doesn't have a clue about auto mechanics!) swears he has been in the industry 20 years and has never seen an O2 sensor after the Cat converter! Well, the parts section says they cannot tell me what is the correct part without bringing it in. Well, if I knew WHERE it was so I could bring in the right part I would. The parts guy talked to a technician, who state that there are 4 O2 sensord - 2 upstream of the "preCAT" and 2 downstream. Is this right?? My Haynes manual (the absolutely most worthless piece of paper ever printed) only mentions that there is a downstream O2 sensor, doesn't say where it is. I tell you this, I would never leave my car there for repairs, since no one seem to know their @ss from a hole in the ground!!![:@]

 

I believe there are only two for the 95-96 cars, while the 97+ has 4. My 97 has 4. Bank 1 is closest to the firewall and has upstream (closest to the plenum) and downstream (PITA to get to without removing the plenum)...Bank 2 is up front and upstream is easily visible just by looking directly down, downstream is close to the oil filter. I mention these in hopes that you might have this setup...doubt it, but just in case. The downstreams that you mention should be on the downpipe portion of the exhaust, not the exhaust manifolds themselves. Unfortunately I don't have my Haynes or Chilton's manual at the moment, so I will get back to you unless someone else chimes in.
The precat is also in the downpipes BTW, it's not huge, it's more like a big snake swallowing a small mouse. The cat is easily viewable, just FYI. See ya in a bit with more info for you.

 

Well, after thoroughly searching for anymore than 2 O2 sensors and not finding them, I went back to the dealer and asked them to find them for me - after about 30 minutes, they came back and said they had made a mistake - it was the rear bank O2 sensor - now, I really don't feel good about letting them work on my car!

Thanx for the input.

 

What manual are you using. I have the 2000 Dodge Avenger and it states that the downstrem is under the car you have to get underneath the car.

 

Who? MMatheny or me? If me then I have the Chilton's, Haynes, and a 97 shop manual. The downstream o2s are better accessible by getting under the car in the 97+ but the 95-96 only two.
If you mean MMatheny, he stated that he had a Haynes manual in his first post.

 

I took my 95 back and told them to show me the downstream sensor - after 30 minutes, they came back with their tail between their legs - said they were wrong, meant the REAR bank sensor - replaced it, no CEL since!!!

 

Good to hear...I would suggest finding a good reliable small garage from this point on though. It scares me to think that the dealership garage didn't know what/when/where/or even how...and it's not even my car, lol.

Oh yeah, another thing that you might find useful in the future is...since our motors are Mitsubishi, some parts are also found at a...Mitsu dealership and may be less expensive to buy at the Mitsu dealership as opposed to the Dodge dealership...oddly enough.

 

mmatheny.....Ok listen I think I am having the same problem that you did and I need some help......Did I understand you right by me thinking you said that there was no downstream o2 sensor. Because I feel like I am looking at two upstream sensors, but then when I go to the parts store they are telling me there is only 1 upstream sensor and I just changed that one. I already changed the one that is right under where the Oil Filter is at. The other one that I am trying to change is like 2 feet farther back away from it and it is before the Cat. Please help would be great.....I am sick of my Engine Light being on......And Oh yeah I have a 1996 Dodge Avenger ES V6 Automatic.
Sincerely,
Michael