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Ford Mustang V6 1994-2004: The Ultimate Air Intake Guide

Make sure you change your air filter on a regular basis and if you are looking for more power, replace your air filter system with an aftermarket cold air induction system.

By Jeffrey Smith - October 6, 2015

This article applies to the Ford Mustang V6 (1994-2004).

The air filter in your Mustang is there to protect your engine. It catches all the nasty dust and pollutants that, would otherwise, get sucked into your engine and cause major havoc in your life. The use of a high quality air filter is a must for your high performance Mustang, but you have to replace them regularly and according to the manufacturer's replacement schedule. If you live in a particularly dirty or dusty area, or you just plain ride your car like it's on fire, you should really consider changing your air filter more often. While the stock air filter works perfectly well at protecting your engine, it doesn't work quite as well as an aftermarket cold air intake system in bringing out the beast in your Mustang's engine. Many folks will part with a nominal chunk of change to upgrade their stock system with an aftermarket CAI (cold air induction system). The reported HP increases at the rear wheels will likely gain you no more than five to six horses, so the choice is yours. In either case, always get the best quality for your car and your budget.

Table of Contents

How to Replace Your Air Filter

Materials Needed

  • Air filter
  • Flat head screwdriver (optional)

Step 1 – Pop the hood and locate the air filter

  • Pop the hood release latch under the steering column.
  • Press down on the hood catch from the front of the car.
  • Raise the hood and secure it with the retaining rod in the indicated slot on the underside of the hood.
  • Locate the air filter assembly in the front-left (passenger's) side of the engine compartment.
Figure 1. Locate the air box in the front-left of the engine compartment.

Step 2 – Open air box and replace filter

  • Pop both clips on the air box housing.
  • Pull the air hose up and out of the way.
  • Remove the old air filter.
  • Replace with a new air filter.
  • Re-seat the air intake hose against the housing.
  • Re-fasten the clips on the air box housing.
Figure 2. Pull up on the air intake hose and move away from the air box housing to gain access to the air filter.

Replacing Stock Assembly

The following steps are performed only if you are replacing the stock assembly with a new cold air intake system.

Step 1 – Remove the air cleaner assembly

  • Loosen the hose clamp that holds the intake hose to the throttle body using a flat head screwdriver.
  • Remove the bolt that attaches the air box housing to the inner fender well.
  • Remove the two electrical wiring harnesses.
  • Disconnect the return air hose.
  • Pull out the entire assembly.
  • Depending upon the CAI aftermarket system that you purchase, there may be additional components to remove from the old air box system that needs to be added to the new CAI system, such as the mass air flow sensor.
  • Figure 3. Disconnect the hose clamp from the throttle body connection.
  • Figure 4. Remove the fender well mounting bolt.
  • Figure 5. Disconnect the wiring harnesses.
  • Figure 6. Disconnect the return air hose.
  • Figure 7. Pull out the old air intake assembly.

Step 2 – Install new CAI system

Follow the manufacturer's instructions that came with your CAI system. Install according to specifications. Make sure to use any parts from your old system if applicable (i.e. the mass air flow sensor).

Figure 8. This BBK CAI didn't come with a mass air flow sensor, so the old one had to be reused and installed onto this CAI.

Featured Video: How to Install/Replace Air Filter

Cold Air Induction System Reviews

An aftermarket cold air induction system can give your Mustang the boost you've been looking for. An aftermarket CAI can help make your car's performance and sound match closely to that of a prototypical V8 muscle car, especially if you add a dual muffler cat-back system along with a CAI. There are many choices out there, so shop around for the best value for you that gets you exactly what you are looking for. Four of the more popular choices are reviewed here to make your decision a little easier.
MAC CAI
MAC Straight Shot CAI
BBK
K&N FIPK II
Price
 $160 $175 $170 $250
Dry/Oiled

Oiled

Dry

Oiled

 Oiled
Construction
 Chrome Polished Stainless Steel Bright Chrome Black Polyethylene
HP Increase (@ rear wheels)
 9 HP 10 HP 8 HP 10 HP
Best Quality: K&N

Best Value: BBK

MAC (Regular)

Price – $160

Dry/Oiled – Oiled

Reusable – Yes

RWHP Gains – 9 HP

The MAC regular (or fender well) version CAI is one of the more popular choices of cold air induction systems among Mustang owners. It is a bit more popular than its straight shot cousin because of its clean look, having the air filter in the fender well. The whistling or sucking noises that CAIs naturally have is much less pronounced in this version, as well. You can expect this system to give you up to a nine HP increase. Recommended for the budget-minded owner looking for the most affordable option with moderate performance gains and a very clean look under the hood.

MAC Straight Shot

Price – $175

Dry/Oiled – Dry

Reuseable – Yes

RWHP Gains – 10 HP

The MAC straight shots are popular among Mustang owners, as well; however, they are a bit less popular than their cousin that hides the filter in the fender well. Given less travel to the throttle body, the cold air of the straights will give you about an extra HP increase over the fender well version. With an overall increase of up to 10 HP, this CAI system is a decent buy at around $175. Recommended for the budget-minded owner looking for a little more HP gains who doesn't mind the extra bulk under the hood.

BBK

Price – $170

Dry/Oiled – Oiled

Reusable – Yes

RWHP Gains – 8 HP

The BBK CAI system is another common CAI among Mustang owners wanting a moderate power increase at a decent price point. You will have to transfer the old MAF sensor to this system, and it is not quite as a clean look as other sensors. The air filter cone is a little smaller than the others, so it is not quite as bulky under the hood. Recommended for the owner looking to maximize gains at a moderate cost.

K&N FIPK II

Price – $250

Dry/Oiled – Oiled

Reusable – Yes

RWHP Gains – 10 HP

K&N is one of the highest quality rated filters on the market today. Their prices clearly reflect their reputation. You will pay almost double for the K&N brand name; however, they are one of the few that offers a non-metal intake tube that won't heat up to massive temperatures like the others are capable of doing. This equates to consistently colder air going through to the throttle body and engine, resulting in the better performance you've been looking for. Recommended for the discerning owner who wants serious, consistent results and only the best quality aftermarket parts will do.

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