still having issues! No Power!

I previously wrote (switched pushrods)

We'll I thought I had the problem licked. But I still have this low end bog, it hesitates and begins to excelerate then it takes off. It acts normal until it shifts then bogs a little then goes agian. I have a cold air intake on the car. I do hear this whistle like a vacume leak when it quits, then that's when it goes. I've never heard that whistle before.

Heres what I done.

I've replaced the intake manifold gaskets because of a leak. I took the air plenum( the upper intake) and washed it out with water and power clean. I had a lot of carbon build up in it.
The injecters were filthy, are the little black ends supposed to spin when you turn them? Three of mine did but the other three were stuck. I used carb cleaner on them and all of the ends broke free except one. I used a pair of plyers and eventually it broke free. The weird thing was that the plastic end was off set and that's why it was stuck. This either happend at the factory or while it has been on the car. I've never taken it apart. I don't know if this could have anything to do with it.

I also changed the spark plugs and wires. I used autozone spark plugs (7mm) and autolite platinum plugs.(.060 gap)

These were the few things that I've done that I can think could have caused any problems. I know there is a sensor in the air plenum(the upper intake with the throttle body) could it have been damaged by the cleaner?

one last thing I started the car after we finished, pulled it forward adn then changed the oil. I noticed that when the oil was changed towards the end it looked milky. I didn't run it but just for a minute. I've checked the oil agian and it looks fine.

I just started having the same problem. last month I had the body control module go out on my car had it replaced at the dealier anlong with havein the 30000 mile service. and transmision service. when i got the car back i ran a little different. its gotten worse. no low end power car seems to jerk until i get to power band. also no high end power. when on the highway i punch the gas transmision downshifts but no acceleration. i get better acceleration when i back off gas trasmission up shifts it accelerates better. anyways. im taking it to the dealer this week to have it checked out. i know its a result of something they done. will let you know what they come up with. i think the computer need reprograming.

i noticed reading thru the threads that you had same problem you bcm
i'm wondering if your problem also started to occur after it was changed.

If your talking anything but the SS 5.7 they are prone to bad catilatic convertors nice costly job unless still under warrenty 1900 CAN one piece exhaust

The Cat was the problem, I've replaced it and it runs great. I will have to put a o2 simulator on the rear o2 sensor. I am getting a check engine light. I didn't go OEM.

just got my car back from the dealer. yeap changed converter car runs great. the cat was under warranty till 80,000 or five years all emmisions control is under same warranty check with dealer

Too far common on them Hummm