Steve83ta

This all started a couple of moths ago although it wasn't bad. The car never threw a code so I was clueless since I don't have a scanner with glitch capture.

How ever this month during the cold I was able to catch at least something wrong.

first off the symptoms. Car starts and runs normally while the fuel system is in OPEN loop mode or power enrichment. As soon as it starts running off the sensors in close loop mode the car falls on its face.... Its starts missing and seems like its running on half or less the half of its cylinders.

But once again, no codes, not even misfire codes, even though it is misfiring like crazy.

I was finally able to catch a problem with my scanner hooked up at one point and I noticed the Fuel trim was pulling all the full out the left bank, -45LT I believe, once again I'm not sure why it didn't set a code for that considering all the missfires.

While I continued looking over all the data I noticed my Bank One Sensor one was Stuck at 1.1mV, along with Sensor 1/2, same at 1.1mV. Just flat lined, not responsive. This problem comes and goes. Sometimes it will not do it for days then it will continue for the next couple.

You guys have any other ideas other then the PCM taking a crap?

The front and rear 02 sensors run on different signal wires as far as I can tell but the wiring diagrams are questionable, also if they were shorted to power in the harness wouldn't the readings be around 5V and not 1.1. Its causing the EMC to remove all full to the left bank causing the car to fall right on its face.

After as bit the O2 will start to respond like normal, but that's after 20 mins of driving and who knows why, heat from the engine?

Also on a side note, this problem was becoming very annoying so I trying to set the engine light to get the ECM to run in default mode ignoring the 02s, I unplugged the MAF sensor and the Intake Air sensor and to much of my surprise the computer went on its way, never even setting a check engine light.

Its been raining the last couple of days so I haven't had a chance to unplug the sensor to see if the ecm still see the same voltages, but its seeing the 1.1 on both front and rear with the key on and engine off instead of the expect .450-.5 while they are hooked up.

Thanks for any help guys, I just don't want to run out and buy a new ECM if I don't have to. Plus a tune, since this is an LS6 engine and not the stock LS1

Home on guys any ideas? I. at my whits ends at this pont. Im looking for some suggestions.

Can you please directory that can help?

Steve
Steve