My left 02 sensor readings are insane. They go from 0-400mv constantly. They do the same thing after it goes into closed loop, however my right 02 sensor readings are correct where they should be in both open and closed loop. Now I know that my 02 sensor on the left is bad, however I was suggested by Ion that one of my fuel injectors may not be firing correctly on the left side as well.... I was curious how I could disable the left side 02 so that it stays around 400mv at all times so I can troubleshoot the fuel problem.

I have freescan, datamaster, and tunercat.

Thanks.

 

Will just simply unplugging the left 02 send it into open loop mode?

 

I believe that it will run in open look if you unplug the o2 sensor.

 

Sounds as if you like to do random guessing. I fail to understand why you would want to troubleshoot anything before replacing the bad sensor. Why disable the bad sensor, AFAIC, it is already..... 'disabled'.

 

How do you know the sensor is "bad"? Could be very accurately recording the erratic results of a problem injector, sticky valve, misfire or some other problem. Sort out the cause, not necessarily the thing you can see.

 

Interception! Fair question. 'Silvershark' can answer for himself later, as he doesn't know for sure, does he? The guy could attempt to verify faulty sensor, by swapping sensor with other side to see if sensor characteristics follow. I consider it important for sensor to output accurate info, to help to diagnose other components.

 

My question was directed at Silvershark, not at you Arnie. I should have used the "quote" commands to make it more obvious.

 

It was obvious, Fred. I was in the vicinity, and just put up my 'hands' to intercept. I was helpless.

EDIT: What I meant to say was.... couldn't help myself. Well, I was close.

 

Injuneer, I know that the left 02 sensor is bad, becuase before I pulled my engine I logged my car using freescan and this is what I received.

http://www.akgaming.com/~kendall/images/enginecodes.jpg

I went ahead and purchased new ACDELCO 02 sensors and put them in the car. I then went ahead and did a datalog and now both side Mv readings for the 02's are fine, and they stay rather close to each other, however my STerm and LTerm values on the left side of my car are really high. (Mind you this is after swapping the injectors from the left side to the right side of the intake, Trying to see if the problem followed the injectors, they did not.)
My left side STerm values get all the way up to 200. I didnt even think that was possible. The LTerm values go all the way up to 143. I have the datamaster log file if you are interested in looking at it. I also checked my histogram and I am getting split BLM's. My left side is showing lean and my right side is showing rich. I had shoebox change my injector constant from 32 to 28 because he believes my injectors are not flowing what they should.

From the butt dyno, the car defiantly pulls a lot harder, however it is no where near 400rwhp.

I will try and get in contact with Racetronix and get some new injectors and see if that clears up my problem.

 

OK.... you're going about it the right way. Fix the known problems, then look for the causes of what's left.

The ST's can go above 160, unlike the LT's. But if your LT's have stabilized, the ST's should be averaging 128 in closed loop, even though they may show an instantaneous value at the high or low end of the scale. A "200" would indicate that for that 1/10th of a second since the last reading of the sensor/adjustment of the pulse width, a slug of air had passed the sensor. You need to find out how that air is getting into the left side. Or why the O2 sensor may "think" there is an upset in the air content.

Are there any high voltage wires too close to the O2 sensor/harness? Is there any external material getting on the outside of the sensor.... oil drips, exhaust fumes, etc.... that would throw off the atmosphere outside the sensor?

Is the left side showing a high LT in all the cells, or just some or them?

 

I am getting split blms. The left side gets really lean only on certian cells, and the same cells on the right hand side are really rich.

I have checked for air leaks, none. No oil, its a brand new motor, no high voltage wires by the 02 sensor.