Also my reader did not show any codes but you can feel the short bucking while driving.

Your scanner tells you fuel pressure even after shutdown.

Looks like a bad fuel pump to me.

How can your car be missing like this and not set codes?

Well, the reader could be lying to me. Should I not have any reading while shut off? And at this point I'm not really sure it is misfiring now. Is there a code for a fuel pump and is it for an electrical issue and not mechanical? Also which pump are you referring to, the pump in the tank or the direct injection pump? where does the reader read the pressure before, at, or after the direct injection pump?

Ok, today I had a mechanic read the codes again, but no mil on. One was traction control, one was transmission and the other was anti-lock brakes, looks like possibly coming from same module. Will be talking to transmission guy and find out more.

Your mechanic is just that. Probably a great guy for doing most any labor job but not so much is diagnostics. What are the codes?

Well he is a heavy duty mechanic that owns and runs a successful shop. He would also be the first to tell you he hasn't had a lot of experience with the scanner he was using or the rest of his mechanics know enough about the transmission codes but he is willing to find out and I trust him. And all shops in town are swamped with work but he took time to go on a test drive with me. as far as codes go I know one was P0711, the other ones I can't remember the numbers just the names I mentioned in my last post.

For some perspective, each of these subjects can have many specific codes attached that would readily change the diagnosis, so:

What about traction control? Disabled? Bad sensor? Etc
What about the transmission? Low pressure? Slip in X gear? Overheat? Intermittent voltage on [name your sensor]? Etc.
What about the anti-lock brakes? Disabled? Bad sensor? Etc.

Kind of like when your doctor asks what is wrong you respond by saying "Chest." Pain? Hole in? Hard to breathe? Heartburn? Etc.

P0711=ECM or PCM has detected a fault with the transmission temperature circuit

Probably not related, but should get fixed, especially on a 8L90 , those things have enough problems while they do know what their temperature is.

In the meantime:

These numbers bother me. I suggest using a real fuel pressure gauge. and get back to us with those numbers.

P0711 will give trans drivability issues, (bucking and or harsh shifts). more than likely needs the internal trans harness due to erratic readings from the trans fluid temp sensor. I have replaced many for this code. GM has a TSB for this. #PIP5700D.