wait we just contradicted each other. hmmmm..... red light, green light, go!

 

*sigh* Way to go CPL...

I agree with your first sentence and your last sentence. That said, I stick by the fact that the aft-cat O2 sensors don't have anything to do with the computer determining the mixture of the car, that's why you can run O2 sims (actually you can just install a series resistor in the O2 sensor wire to trick the computer if you're soldering savvy) and it doesn't effect your mixture at all.

 

hehehe. So you agree that you missed his OP in the other thread and that death causes cancer? I know..... I dont know nuthin about nuthin about o2 sims. nuthin. couldnt tell ya. I can SWAG it but I wont. So, with that said I will respectfull bow and refuse to create contention, untill I am adequately educated on the subject.

 

so much feedback....thanks guys !!! im sure theres a lot more problems down the line. the front O2 sensors are working fine its just the rear. ill take a picture if that helps?

 

No, we got the idea. lol. We both do agree that they need to be in the tube instead of hanging out of it. Summit has some bungs.
I think once you get them in, have the codes cleared and drive it for a while you will have a better idea of whats going on.

 

If you put the rear O2 sensors in an off road Y pipe it's not going to fix your SES light since there's no cats for the O2 sensors to monitor. If you get O2 sims you will actually unplug your physical O2 sensors, set them aside for when one of your pre-cat O2's dies, and you put the sim in place of the real O2.

When you go the codes read, aside from Catylitic Converter performance, what other codes did they read out?

 

rich in bank 1 and 2 ...hold on ill get the codes tomorrow

i do have a cat too btw

 

*shakes head* Now I'm confused...

Can you do us a favor and list all of your current modifications so we can try and provide you with the best possible information for your specific situation...

If you're running lean bank 1 and bank 2 that's all of your cylinders. Since it's all of your cylinders, either both of your pre-cat O2's went bad at the same time (seems unlikely, but it could happen) or you may be having some sort of fuel delivery problem.

 

Something to keep in mind. An ignition misfire will cause a rich mixture condition due to raw fuel entering into the exhaust system.

How the OBDII O2 system works.
Pre cat sensors (upstream) provide the main input to the PCM during closed loop operation.
The post cat sensors (downstream) monitor the efficiency of the cats.

The pre-sensors produce an output signal, which indicates the amount of oxygen present in the exhaust gas entering the 3-way catalytic converter. The post sensor produces an output signal which indicates the oxygen storage capacity of the catalyst. The oxygen storage capacity indicates the catalyst's ability to efficiently convert the exhaust gases. If the catalyst is operating efficiently, the pre-HO2S signal will be far more active than the signal produced by the post HO2S.

In addition to catalyst monitoring, the post (downstream)-heated oxygen sensor has a limited role in controlling the fuel delivery. If the post-HO2S signal indicates a high oxygen content or a low oxygen content for an extended time while in a closed loop, the PCM adjusts the fuel delivery slightly in order to compensate.

 

Did any of you guys have to use o2 extensions when you installed your headrs? Just wondering because I am about to order mine and thought i might need them and would hate to order the headers then have them in and not have my o2's reach.