I'm losing serious HP. Options

[cHinaman727]

About 3 weeks ago my car started idling funny. The needle always shows around 900 but when I got it inspected, the dyno said it was jumping down to 700 and back. Also, when I take off from a dead start in first gear, it is almost like I have the AC on, it takes a while to start moving. If I have the AC on, it took me almost 3 seconds to get any HP at all.

Also, when accelerating, the car is much more sluggish than before. After I get to around 3000 RPM's in 2nd or 3rd gear, its like the HP jumps back in but then sputters randomly.

I don't know what to do and I don't have much money!

[Remy]

The CE light is not showing.

What would I check on the spark plugs?

Randomly, in the past, I will be accelerating (when it was normal) and right after I shifted into 3rd I would hear this large bang sound like air exploding out of a compressed container. Thats what it sounded like to me anyways.

Since I was driving I couldn't be positive if this was from my exhaust or my engine bay, but it sounded more to the front of my car.

I notice in S54's that 3rd gear likes to grind over time I'm sure thats what the noise was (either that or it was a misfire) when did you last replace your clutch ??