95 TSi AWD - how many oxygen sensors?

[euroticcustoms]

Hey guys, I have a 95 TSi AWD that hesitates and runs rich at certain RPM's. Apparently somebody pulled the bulb for the CEL...but I hooked it up on my buddy's MODIS today and it said that there was a malfunction on Oxygen Sensor BANK 1 SENSOR 2, Heater Circuit. There were two codes...can't remember EXACTLY what they said but they both had to do with the #2 oxygen sensor on bank 1. I have an RHR Racing 3" turbo-back exhaust system, which was installed on the car before I got it. I checked for 2 oxygen sensors but can only find one in the manifold. I searched this site for "oxygen sensor heater circuit" and it brought up like 10 posts...read the one closest to mine and it said "sounds like your oxygen sensor is toast...it's located in the manifold...costs like $75 to replace." Well I went to www.advanceautoparts.com, and the website says there's an upstream and downstream. Upstream being in the mani, and downstream being near or in the cat. It even listed different downstream sensors for FWD and AWD cars. I kneeled down and looked under the car to check for a downstream sensor and couldn't see one...didn't jack the car up and check, but...I was just wondering if there is actually supposed to be a downstream sensor on my car...and maybe if whoever put the exhaust system on it may have just cut the plug and removed the CEL bulb. Anybody have any info or suggestions? I'm getting BAAAADDDD gas mileage and a stock 95'ish sunfire was riding my tail today...I punched it and I went from like a 20 ft lead to a 2 ft lead and couldn't shake him...it's running bad, please help Thanks ahead of time.

Paul

 

[Old Mitsu Tech]

B1S2 is behind the catalytic converter. It was probably removed. I would look for a square connector with probably 4 pins somewhere in that area. Hopefully they didn't cut the connector off. This o2 sensor keeps track of the effeciency of your catalytic converter. If it's been removed that is your code. This can cause rotten fuel milage. My mom's Neon had a bad one and she was very happy with the change to her mpg when I replaced it. As far as running really ratty, I doubt that the rear o2 is the cause. Scan for codes and give us a few more specifics. I would check compression, timing etc. for anything that may not be right. Without hearing it run it's almost like you telling me what a banana tastes like by my reading about it bearing in mind I haven't tasted one before. Be very specific. This will help in reply diagnostics. Good Luck