No....you have a sensor on each pipe before the cat and a sensor on each pipe after the cat.There are 4 total......the upstream sensors are before the cats and tell the PCM how much fuel is needed to reach stoich.The only thing the downstream sensors do is monitor the emissions.Sensor 1/1 is driver side pre cat.....2/1 is pass side pre cat........1/2 is driver after cat and 2/2 is pass after cat......hope that helps when reading codes.
[Edit - dammit. looks like it took me 11 minutes longer to write this than Erik took to write his -- and who says mechanics can't type?] You should have 2 of those things on each side. One should be in front of the catalytic converter and one after it. Upstream/front of the cat and downstream/back of the cat. The front sensor on the driver's side would be Bank 1 Sensor 1, the rear sensor on the driver's side would be Bank 1 Sensor 2. Driver's side is bank 1, passenger side bank 2. The front sensor is used to monitor your a/f in closed loop mode (just driving around). The rear sensor reading is compared to the front sensor reading to see how well the catalytic converter is working. The PCM will monitor the sensors for open circuit and the sensor heaters ALL the time whether it is monitoring the sensor O2 readings or not. The first code is indicating the PCM thinks there is something wrong with the front sensors or circuits. It's complaining about both sides... The catalytic converter efficiency codes are because the PCM doesn't like the comparison of the front sensor reading to the back sensor reading. This could be because of the problem causing the first code. Or it's just outside of the difference it expects with normal cats.
Their is another guy on the Cherokee side having the same problems after a header change http://www.cherokeesrt8.com/forums/showthread.php?t=15301
Im gonna try the anti foul spacers on the rear 02's first and see if that clears things up. I don't for a minute doubt that my installer bent up the front 02's on reinstall, but will try the easy stuff first. Thanks to all for the help. btw anyone know the thread size of those 02's?
**Update** Installed new upstream 02's, didn't do squat. I did however get my 12 month waiver today In the rules it states not messing with factory emissions equipment, but it doesn't seem to matter here thank goodness. I don't see there being a problem doing this every 12 months if need be. Thanks to all for hints/tips for trying to figure it out!
How did you get the 12 month waiver? My emissions test isn't until 2011 but I suspect I'll have to hook another car up to the sniffer as my own.
Have all sensors ready and go to inspection station and get a failure. Spend $200.00 or more trying to fix whatever the initial inspection report said was wrong. In my case....slow 02 response and inefficient cats. Go back to inspection station, get another failed report showing the same type of failures as the initial one. Take to regional inspection and theft inspector (in NC we have one for every 3 counties or so). They will print a piece of paper allowing your regular inspection station to print an inspection sticker. The process also leads me to believe you can do this repeatedly. Initally I didn't go this route because the law states you can't alter the cars factory emissions equipment. They didn't seem to mind, so I may have just gotten lucky.
Sounds like the main thing is that you put at least $200 towards trying to fix the failure and then they'll give you a waiver. You'll just have to spend a couple of hundred each year. (I wonder if buying BT parts would work?)
If Heidi can put O2 sensor on the bill, then it would work just fine :friends: The receipt has to have some indication that it was work done to fix the failure problem.
Well I finally passed NY state emissions testing today Only took me 6 months to do it, lmfao. The anti foul spacers did the trick. I fought it for a long time but believe it or not, they worked perfectly. I put two on each rear 02 sensor. One longer one and one shorter one stacked. I forget the part numbers but if someone is in need, Ill look it up. Got them at Autozone and drilled one of them out on each side so the sensor would fit into it. Make sure your tune does not have the rear 02's turned off and put these puppies on. You should be able to get into ready status in 2 days or so. Turn your key to the on position and watch your Check Engine Light. If it stays steady after 15-20 seconds, you are ready to test. If it starts to blink, you need to put more miles on the car. I know its been covered, just wanted pass on how it worked for me
Thanks Dan. The part numbers would be very helpful when you get a chance. I copied this post and saved it in Word.
Here they are, get them at autozone. 18mm is the thread pattern. You will have to drill out one with the largest drill bits you have so the 02 sensor will fit into it, 1/2 inch off the top of my head. Then put that spacer into the other one without drilling it. Here is the thread I got some info from http://www.lxforums.com/board/showpost.php?p=670555&postcount=1
