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Pain in the butt O2 sensors

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dgproctor73

CEG'er
Joined
Dec 28, 2008
Messages
73
Location
Southwest Michigan
I've been on here umpteen times, researching this before I asked any stupid questions. 1998.5 SE V6, when I got it was throwing 1519(IMRC stuck(fixed),0171(too lean B1),0174(too lean B-2). So I put three new O2 sensors in (both uppers, lower pre-cat), new plugs, new ford racing wire set, new Accel EDIS coil pack( old stuff looked horrendous ). Had the codes reset, and now it's throwing 0136 (bank 1, sensor 2). When I removed the bottom sensor it had a relay or something wired to it (possible mil eliminator?)!? Just can't figure out why its doing this. Was going to go get the first muffler cut out, and replaced with straight pipe, but am very apprehencive now! Any old forum, or ANYTHING would be greatly appreciated.
Thanks, dgproctor73
 
[FONT=arial,verdana,helvetica,sans-serif]P0136[/FONT][FONT=arial,verdana,helvetica,sans-serif]Downstream Heated Oxygen Sensor circuit fault - Bank No. 1. [/FONT]

was this one of the sensors that you replaced or is this the one that you discribed as having something wired to it? its possible that it has a mil-eliminator. if that was damaged or came apart I think it would give you a circuit fault code.

got a pic of what you are talking about?
 
It was on one that I replaced, after replacing three of four it's throwing 0136. And I know the guy at autozone is starting to hate the sight of me. It's my family's only vehicle so I'm kind of animate about fixing it, well that and its cold here in MI!!
 
ok so you repalced the down stream sensor that had something wired into it? confused and want to make sure I have things straight
 
Both uppers, and yes the lower one had something wired to it, and yes I replaced it. If I was thinking I'd of snapped a photo of it, but it was late! That and the wife was riding my ass, so you miss things of this nature, well until brought to ones attention!
 
I dont understand why your car would have a mil eliminator on it to begin with. I cant imagine why someone would have put one on it.

you really need to take a picture of what you are talking about. Which downstream sensor did you replace?

Gawsh I wish we had NECO's smileys, I wanted to use the this thread is useless without pics smiley.
 
FunInNorthDakota said:
I dont understand why your car would have a mil eliminator on it to begin with. I cant imagine why someone would have put one on it.
...
Click to expand...
If the previous owner had a P0420 code, installing a mileliminator for the Bank 1 Lower Sensor would eliminate the code. If the wiring were broken, a P0136 would occur.
 
Sorry I can call my buddy and see if he still has the old sensor, I have no garage:shrug:!!! I replaced the pre-cat sensor (in the 180 degree bend). When I got the car the check engine light was on so I reset the computer (thanks CEG), and had it tested when they came back on.1519,0171,0174 researched the old forums, replaced the parts I figured them to be, and a couple new. Reset the computer (and codes), made it about 50 miles before they came back on (just the 0136 code now). As I said any input would be immensely appreciated!!
Thanks, dgproctor73
 
if there was something added into the harness it probably was a CEL eliminator. but if you arent throwing a code for the catalyst not working then you probably dont need it.

I would be looking for broken wires or bad connections personally.

I could swear that I have 2 downstream sensors on my 98. Both of them come after the precats, well, now after the collectors on the headers. Anyways thats why I was wondering which O2 sensor you replaced. But I guess it would be a mute point since you arent throwing codes for catalyst inefficiency you are throwing codes that your O2 sensor isnt working.

Bank one would be the downstream sensor on the rear manifold.

anyways, knowing which of the two sensors you replaced is key. Did you replace the sensor after the front precat or after the rear precat.
 
FunInNorthDakota said:
if there was something added into the harness it probably was a CEL eliminator. but if you arent throwing a code for the catalyst not working then you probably dont need it.

................... But I guess it would be a mute point since you arent throwing codes for catalyst inefficiency you are throwing codes that your O2 sensor isnt working.

Bank one would be the downstream sensor on the rear manifold.
...........
Click to expand...

3 inaccurate statements here.

You need the mileliminator to prevent the P0420. If the wiring is broken at the mileliminator, you will get a P0136 (or P0156 Bank 2). I've had this happen to me more than a few times.

Bank 1 is Firewall side (or Rear manifold), not downstream. There is an upstream and downstream O2 sensor (for both Bank 1 and Bank 2 manifolds).
 
Tony2005 said:
3 inaccurate statements here.

You need the mileliminator to prevent the P0420. If the wiring is broken at the mileliminator, you will get a P0136 (or P0156 Bank 2). I've had this happen to me more than a few times.

Bank 1 is Firewall side (or Rear manifold), not downstream. There is an upstream and downstream O2 sensor (for both Bank 1 and Bank 2 manifolds).
Click to expand...

sorry the code he was throwing was for a downstream sensor on bank one. I meant to say that his problem would be the downstream sensor on the rear manifold (firewall side)

As for the other ones there, I dont see how what I said was inaccurate, I was just trying to simplify it. I said if he had something attached to the O2 sensor it probably was a Mileliminator. I find it strange that he would have gotten the car with one installed but meh. I said if he isnt throwing codes for catalyst inefficiency then he doesnt need to worry about a mileliminator. I said that the code he was throwing was basically saying that his O2 sensor wasnt working. And that he needed to look for bad connection/broken wires
 
FunInNorthDakota said:
....As for the other ones there, I dont see how what I said was inaccurate, I was just trying to simplify it. I said if he had something attached to the O2 sensor it probably was a Mileliminator. I find it strange that he would have gotten the car with one installed but meh. I said if he isnt throwing codes for catalyst inefficiency then he doesnt need to worry about a mileliminator. I said that the code he was throwing was basically saying that his O2 sensor wasnt working. And that he needed to look for bad connection/broken wires
Click to expand...
If the previous owner installed a mileliminator and did not take it out, then the new owner gets a car with a mileliminator. If the wiring for the mileliminator came out, he will get a P0136 (Bank 1). The moment he installs a new O2 sensor, he will end up getting a P0420. So he needs to fix the wiring for the O2 sensor.
 
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