This appears to be separate from the misfire because it is way too consistent and my misfire isn't. When I step on the gas in first gear, the car loses power briefly for a half second at 1300 rpms. It's like fuel pressure just gave out for half a second, BUT with the fuel pressure gauge on there is no change in fuel pressure when this happens. Really puzzles me. TPS or IAC? I have no idea. This has been an ongoing issue for a while second to the misfire. But man, if I hit the gas, no matter where it is that car roars to life.

 

The IAC wouldn't cause that problem.

You can check the TPS easily. Key on, engine off, measure the voltage between the gray wire and the black ground wire. Should be 5V. Closed throttle, measure the voltage between the dark blue wire and the black ground. Should be between 0.20 - 0.90V. Some people prefer a number between 0.50 - 0.67V, and most of the stockers I've seen measure around 0.67V, but the PCM can accept anything between 0.20 - 0.90V. If it was outside those values, you would already have an SES light and a code. Wide open, the voltage should be roughly 4V higher than the closed throttle voltage.

Now start at closed throttle, and slowly open the throttle blades all the way, while watching the voltage. Should increase smoothly, with no spikes or dropouts.

A more likely cause would be a tear in the inlet elbow, or the elbow not being tight on the bottom of the throttle body. Or a problem with the MAP sensor. The PCM looks at the MAP reading and the rate at which the TPS voltage is changing, in order to anticipate increased air flow, while waiting for the MAF reading to catch up to the sudden increase.

 

And off I go for more testing. Thanks man! Appreciate it as always!

As a matter of fact, when I put the inlet elbow back on, I accidentally didn't get it on all the way and the car idled really really crappy. I probably did the same mistale twice as I was in a hurry. :-/