Anything to the engine -- nothing since I replaced my CAI with a K&N filter instead of a Ractive filter. I do want to check/clean my MAF sensor wires, strictly because of the new filter possibly having too much oil on it and fouling the wires.
Odd sound and no power -- yes, the odd sound is the CAI 'whooshing' (if you have a CAI, you know the sound) VERY loudly. At 3/4 throttle, there'* a very definite change from the previous bogging to normal power.
Good power and normal in high RPM -- yes.

I agree with you, it'* not a fuel pump or plugged cat.

Recent development: When I first start driving, it runs normally. About 15-30 seconds into a drive cycle though is when it starts acting up. If I'm driving and flick the key off and back on again (to reset the computer), it drives normally again, until 15-30 seconds later and it'* back to bogging again.

If the plugs were replaced before I bought the car, it would have been apx. 30K ago. Definitely a possible problem, but the way it'* running leads me to believe it'* not an ignition issue.

When I get home from work, I'm going to pull the MAF sensor and clean the wires and pray that it helps.

Thanks guys!

Did you oil the K&N or just drop it in new?

I agree...could be a bad maf.

UPDATE: As a quick test, I unplugged the MAF sensor (to force it to run on the default tables) and it runs better (not perfect, but MUCH better). When I get home from work I'm going to try cleaning the wires and see what happens.

I think I've nailed it.

Cleaning the MAF sensor wires, which were pretty dirty, helped a bit. After hooking the sensor back up, the problem was still there. On a hunch, I unplugged the EGR valve. That completly took care of the problem. Reconnected the EGR, and the problem returned. Disconnected it again, all my symptoms disappeared again. So for the time being, I'm driving around with my EGR valve disconnected.

Now, more questions!
1. What adverse effects will occur with my EGR disconnected?
2. Can my EGR valve be fixed?
3. Are EGR valves made out of gold? Is that why they're over $200? (just kidding...i know it'* because there'* small pixies inside. but i digress.)
4. Anything else I should know?

I'm going to research some of this myself as well, and I'll post what I find if nobody with some experience with this issue replies.

yeah on my 94 l27 my wires were DRENCHED with oil and dirt (great oem filters gm makes )....

Unpluggin the EGR will set off the SES but will not cause too much power loss (however I did notice the PCM did tone things down it seemed, or maybe it was me)

EGR can be obtained on ebay sometimes btw...it is very universal..also try gmpd

also have you tried cleaning the egr with tb cleaner???

Have not tried cleaning it yet, I've actually been waiting for the motor to cool down so I can try that. And since it'ss 11pm, it probably won't get done until tomorrow. I'll keep this updated as things progress.

I've had luck cleaning the EGR. Sometimes it may be sticky. Cleaning the MAF and EGR should help greatly.

How would you go about cleaning EGR?
Thanks and sorry about dumb questions quite the newb if you havent noticed but you guys have been great.

I believe that I know, but I want to hear from one of the gearheads or somebody who has done this before to know the correct way to do it.

95+
Stop off and buy an EGR gasket. When the engine is cold (EGR is exhaust and very hot if the car has been running) remove the EGR off the EGR support. There are two 10 or 13mm nuts. With carb cleaner spray inside liberally gently pushing the pintle valve to ensure it moves freely. (It has a spring behind it and should push in and spring back easliy)

Clean old gasket area and reinstall with new gasket.