Usually I can find aanswers with a hour of searching forums. My girlfriends Saturn started acting up a few days ago, bogging out and being hesitant. I took the car to auto zone and it came up the bank one sensor 2 heater circuit...... Well reading on forum this will only cause low mpg. In my case I can't drive the car or rev the motor past 2500 rpm. To me it sounds like it's not getting proper air fuel ratio. Someone told me gut the cat and buy a new sensor. Thanks for any help. Also that was the only code present

 

The rear O2 sensor is supposed to just monitor the efficiency of the cat, but it actually has some control over the long term fuel trim.

Gutting the cat is NOT good advice. If you do that, you will get a constant P0420 code and your long term fuel trim will fluctuate too rapidly to control the engine efficiently.

I think that first, you need to get a code reader hooked up again and see if it is really producing a P0141 code. You need to personally see the code on the code reader, do not take the AZ employee's word for it. The reason I say that is because in a 2000-2002 saturn, the P0141 code does not appear to be monitored, only the P0140. A defective heater can produce this code, but so can a defective sensor itself.

If it is a P0140 or a P0141 code, just replace the rear O2 sensor and be done with it. If the cat went into meltdown, you will need to replace it, not gut it. If you have a warmup cat built into the end of the exhaust manifold (looks like a tin can welded to the manifold), then that would be the cat that most likely melted down and the whole manifold has to be replaced.

You didn't hear this from me, but you can gut that cat and the system will work as long as the engine is warmed up, but you may be plagued with a chronic P0410 code if you do. That is the secondary air system, most people think it is a bad blower motor, but it usually is something else because the blower motor operation itself is not monitored.

 

I actually was the one who hooked the reader up. I have it written down at home but I know for a fact it said bank one sensor two heater circuit......just wasn't sure if it was the p0141 or p0140 guess I got confused reading other posts. second question I have is will the universal from bosh work for this car and does any one know where l can find a wiring diagram for that if it works.

 

Also, if this is only the o2 sensor how come everyone else who has come across this problem still able to drive without it bogging out and hesitating. I know you said it has some control of fuel regulating. Just crazy no one else has come across this problem.

 

I checked the Haynes manual to see if the P0141 code was valid for some Saturn models and apparently it is for 96-99 models. The Haynes manuals doesn't have troubleshooting procedures though.

The O2 sensor should have a very high internal resistance when cold so that the system detects a default bias voltage. The bias voltage is used for the open loop operation. Does the car run sort of normal when cold and then bog down after it warms up? If so it is because it is in open loop and treats the engine like its cold. Other than that, you could have more than one problem.

I would pay the extra money and get the exact fit sensor. But if you want to use a universal, I can give you the wire colors for a 2000-2002, but the HO2S for 2000-2002 seems to be different from the 96-99, at least as they are listed in the Rockauto catalog. BTW, Rockauto.com is quite a bit cheaper than AutoZone.

Heater + pink wire to pin D
Heater - black/white to pin C
sensor wire tan to pin A
sensor wire purple/white to pin B

Hope this helps, it is all I can do for you right now.

 

i have found my s cars to prefer DENSO O2's over the years. Plus it's plug and play (and time = money)

EDIT: Prefer DENSO. hate Bosch. Spaced out there ---sorry

 

Stop in the new member area and give yourself a proper introdutin...Than take a minute and go to the USER CP top left of most pages open "signature" and add your first name, location, and car info.

 

Cold or warm it bogs. I will take a video and post the link. I really appreciate all the advise and sorry for no introduction. I'm just a busy guy between roofing and trying to get all 3 of my cars fixed since they all decided to break down at the stime