Sluggish Acceleration, poor shifting (auto) & sputter/popping from cold air intake
 

Posting this after reading several related posts which were helpful but did not provide a clear cut solution for the problem I was experiencing.

The Auto
1999 Protege LX with 1.6 liter and automatic transmission. 95,000 Miles.

Problem/Symptoms
Car was running flawlessly until one evening the vehicle was found to be totally without power. It turned out that I had failed to tighten a battery terminal clamp and I reseated and tightened the clamp. I did so with the key in the ignition and in on position (yes, very stupid). When I started the car, I found the following symptoms had suddenly appeared:
[LIST=1]
1. I heard a light popping or sputtering sound coming from "from" the air filter housing. It was not particularly loud.
2. The idle dropped from around 900 - 1100 RPM to 700 - 900 RPM and faltered, close to stalling.
3. The car had a marked hesitation and very sluggish acceleration.
4. There was a delay in the shift between gears (auto transmission) and the shift was somewhat hard.
5. Once the car was at highway speed, it seemed to cruise without any problem save for the fact it would sometimes slow down even with consistent pressure on the accelerator.

TROUBLE SHOOTING.
1. The check engine light did not come on and a scan revealed no codes.
2. Found a loose seal on air filter housing and corrected (no improvement).
3. Checked hoses for vacuum leak (none found).
4. Checked PCV (good)
5. Pulled MAF sensor and cleaned using MAF sensor cleaner (no improvement).

SOLUTION.
Although there were NO codes generated, the symptoms were symptomatic of a bad MAF Sensor. Cleaning using MAF cleaner did not help. I did not have multimeter to test the MAF. I decided to take a chance and just replace the MAF sensor. Spent $80.00 on a new MAF. Spent five minutes installing it and that took care of the problem. No popping sound. Idle was back to normal. No sluggish response on acceleration. Smooth shifting. No loss of power at highway speeds.