I keep getting an SES light and when scanned I believe the book said something about fuel additives or something.

This is my thoughts

Dead O2(s) I ran the O2's with new headers, and I ran a small amount of leaded fuel in it.

What do you all think?

It will just start to run really rough flat ground, up hills. SES light will come on and off randomly. The stutter is a bogging feeling.

I will go get it scanned again somewhere but I wanted opinions first because I think it is an O2 or both O2's.

 

Get the EXACT numerical code. There are no codes for "fuel additives".

Without that, you're just wasting your time and problably some money.

 

Ironically I was thinking the same exact thing, ill get it scanned sometime and bump this thread.

 

Just a bump was scanned today

Passenger side O2 lean, I am guessing breaking in my headers and that 2 gallons of leaded done it in. Replacing tomorrow I will update.

 

Replaced O2 runs better than before it seems lol, wonder how long it has been going bad.

Cliffs: O2 was issue.

 

Did you reset your computer by unplugging the positive side of your battery to reset the fuel adjustments? I made the mistake of not doing that when i changed the o2s, I believe it took around 50 miles to sort out by itself. When i replaced them the second time i reset the computer before i turned the car on and what a huge difference!

 

Err no I never forgot, ironically enough soon as I go on a long trip it starts messing up again Really bad, bogging heavily barely any power, at a red light I could hear something rattling A LOT, do you guys think it could be the muffler heat shield grounding out the O2? Once I went 40 miles or so the SES finally came back on (and stayed on) and the car ran way better.

Which leads me to my next question, will the pcm force itself into open loop?

Seeing as open loop does not use the O2's.

 

Quit guessing and get the code. Anything else is a waste of time, and eventually money. The code sets - it runs better. Scan it. The cause will be obvious.

 

Maybe I am confused, it has been scanned twice, scanner indicated open circuit/lean o2 the passenger side O2 was like 5mv.

 

do you have a DMM? You can disconnect the o2 sensor and measure the resistance between the signal wire and ground of the pigtail. As the signal is a voltage signal, there should be a high impedance input, if the resistance is low, under the Kohm range then you probably have a short. If not then there is a good chance your sensor is bad. You can try reading the output voltage of the sensor with the DMM (car must be on) to see if you get any D voltage output. It should change very fast but you should get an average around .75V or slightly higher.

 

And you have verified that is the code you are getting this time when the SES light came on? You did not say you checked the code after that, or whether is was the same code.