58 should be enough, but I know that GM says 60+

 

yes he agrees the ideal reading is 60+ psi, and 58 should be fine. what sux is i have no codes, even when it does that jerking/hesitation move.

 

Have you tested the TPS sensor (~0.5V at idle to ~4.5V at WOT with a smooth transition between the two)?

Cleaned and inspected the MAF sensor? How does it run with the MAF sensor disconnected?

 

yes that sensor was reading that at idle. i havent cleaned the maf sensor in a while.

 

The fuel delivery system is not directly monitored by OBDII and can not set DTC's if there's a problem with it. No SES light and no codes could be an indication of a fuel delivery problem. 58psi is a problem. GM "dealer issue" shop manual says 60psi to 66psi with key on, engine off and remain above 55psi for 3 to 5 minutes after the pump shuts off. If the check valve in the fuel pump is not sealing properly, leakdown will be excessive, and can also cause low fuel pressure.

 

yea but the guage can also be off in my benefit or against me. explain a leakdown test to me. cuz its about $400 for a fuel pump. process of elimination dont work when parts start getting that high in price. so i dont know what to do. he wants to take off one cat at a time and drive it to see if it still does it. so yea i guess i will start with that. any other guess's at this?

 

If there's a question about gauge accuracy, get another gauge.

The fuel pressure and leakdown test take about 10 minutes to complete. It checks the entire fuel delivery system from the pump motor up to and including the fuel pressure regulator. If it fails either part of the test, a problem exists. It does NOT tell you what the problem is, further diagnosis will determine what the problem is.

Key on, engine off and cold, fuel pump running, pressure must be 60psi to 66psi and must remain above 55psi for 3 to 5 minutes after the fuel pump shuts off.

 

It' is starting to sound like a vaccum leak if the fuel press. is ok. You have fuel, spark, and a new LIM gasket, assuming fuel is good (might be useful to replace the fuel filter to see if fuel pressure increases), you are a little low and that may affect it with sudden WOT. What happens if you only mash the pedal half way?
(assuming no water in fuel, drygas may help) it is usually timing or vaccum. A vaccum test can tell you many things and does not cost $. It can also indicate whether there is a leak, the timing is off, or other more serious things if read correctly.
It might be a good idea to return it to the condition prior to the problem developing. If I understand correctly, this began after installing a CAI. Have you tried putting the stock air box back on?

 

i have a brand new fuel filter on it. tryed complete fuel system cleaner and drygas at diff times, didnt seem to really help. no i didnt attempt to put the stock air box back in yet, cuz it starved it badly. i use to get this loud noise when accelerating with the stock one felt like something was unbalanced or something, put this one in and now no more loud noise. so im stuck right now at a stand still.

 

any more ideas?