Replace your thermostat.
getting the engine worked on and put in a cold air intake
You need to replace the shifter switch (parts and labor cost me $150) -- I finally just had this fixed on my 1992 Integra, and am very happy to be done with this annoyance!
I would suspect a clog in the radiator.
A 1994 Acura Integra using R134a refrigerant should ideally blow air at temperatures between 38°F to 45°F (3°C to 7°C) from the vents when the air conditioning system is functioning properly. If the air temperature is significantly warmer than this range, it may indicate low refrigerant levels, a malfunctioning compressor, or other issues within the AC system. Regular maintenance and checks can help ensure optimal performance.
Check your relay which is under the instrumental panel on the left. When you are seating down on the driver seat, it will be above your left leg. Look for cold solder and re-solder it.
It has not had time to go through the whole radiator
Rubber suspension components contract in lower temperatures and become less pliable--the noise is most likely from the spring hat and/or swaybar bushing. Douse both with silicon spray.
From 5 to 10 horsepower.
Do it when the car is cold if the radiator is hot fluid may be forced out when you take off the cap.
Remove the radiator cap ONLY when the engine is cold.
You do not have one. Disconect the lower radiator hose. (after cold)
Depends on which cold air intake you install. Some years back, SCC did dyno testing with a wide range of aftermarket short-ram/cold-air intakes. I believe the highest horsepower gains were attained with Injen and AEM. During the warmer months, an advantage of using a cold air intake is to prevent horsepower loss from elevated engine bay temperatures.