Ford Taurus P0303 Trouble Code – Track Down Misfire

Engine misfire is never a fun problem to have in your vehicle, regardless of make or model. This is especially true in a random misfire event, where your OBDII check engine code is a P0300 and it doesn’t tell you which cylinder is having the issue. Today I’ll be showing you how to track down misfire and test your ignition and fuel components in a 2003 Ford Taurus SEL. This vehicle is equipped with the 3.0 liter Duratec Ford engine, and it’s experiencing a cylinder misfire issue in cylinder #3. Using a OBDII scan tool we learn that our vehicle has a Ford Taurus P0303 trouble code stored in the On Board Diagnostic computer.

This Ford Taurus P0303 check engine code is a clear sign that cylinder #3 is the culprit. This guide will show you how to take apart your engine to access the rear spark plugs on your Ford Taurus V6 engine. Although this guide is specifically for the Ford Taurus P0303 trouble code, you can use it to gain access to cylinder 1, 2 or 3 which are all rear facing in your Taurus. Because of this placement and the intake manifold, you’ll have to remove the top half of your engine in order to reach your back cylinders.

Before you can track down, diagnose or check your engine misfire in your Ford Taurus, you’ve got to be able to reach all the cylinders. This guide shows you how to find misfire in your engine and get rid of it. We’ll start with the removal of the intake manifold to reach the back three cylinders.

Removing your intake manifold

Before you can correct your Ford Taurus P0303 trouble code, you’ve got to reach the back three cylinders of your 3.0 liter Duratec V6. In order to do this the intake manifold must be removed, and the fist step is to remove the air intake tract. There are two 8mm bolts that hold the upper air box tray in place, these must be removed. The first is located near the driver side fender well.

Ford Taurus P0303 Trouble Code

There’s two 8mm bolts that hold this top half of you Taurus air box. Once this fenderwell is removed then move onto the other 8mm bolt before the driver side shock tower.

Ford Taurus P0303 Trouble Code 11

Loosen the clamps that hold the top half of your intake box to the lower section. From here you must disconnect your mass air flow meter by depressing on the engine harness.

Ford Taurus P0303 Trouble Code 1

When you have these metal straps unclamped, you are ready to disconnect the vacuum lines from your PCV valves and your valve covers on your Duratec.

Ford Taurus P0303 Trouble Code 9

Using a 8mm socket you can now undo the metal clamps to your throttle body. You don’t need to undo the clamps to the MAF housing, just the throttle body union. Now you can remove the intake snorkel and the MAF housing as a complete unit.

Ford Taurus P0303 Trouble Code 12

Now that the Ford Taurus intake system is out of the way, you can continue our Ford Taurus P0303 DIY tutorial. There are several electronic components you need to unplug and undo, starting with the EGR purge valve. There are two vacuum connectors going to this solenoid, as well as a electronic harness.

Ford Taurus P0303 Trouble Code 18

The throttle position sensor for your 3.0 liter Duratec engine should be next to disconnect.

Ford Taurus P0303 Trouble Code 2

The EGR valve on your intake manifold is held on by two 10mm bolts and two 10mm nuts. Remove the nuts to disconnect the valve from your intake manifold, and the bolts to disconnect it from the exhaust tube.

Ford Taurus P0303 Trouble Code 20

At this point there’s just the Ford Taurus fuel damper left to disconnect.

Ford Taurus P0303 Trouble Code 13

Now there are the 8mm bolts that secure the intake manifold to the lower runners. Make sure to take your time here and once all the bolts are loosened, you can lift up on the bolt to remove the plastic guide and the bolt itself.

Ford Taurus P0303 Trouble Code 14

Begin with the front 8mm bolts first on your Taurus intake manifold.

Ford Taurus P0303 Trouble Code 16

Then make your way towards the rear bolts and evenly loosen all of them. Now remove the 8mm bolts and plastic guides.

Ford Taurus P0303 Trouble Code 17

You should now be able to lift up on the intake manifold and set it towards the driver side fenderwell. This gives you enough space to reach the back three cylinders on your Taurus. These include cylinder 1, 2 and 3 on the back of your 3.0 liter V6 Ford engine.

Ford Taurus P0303 Trouble Code 27

Now you can pull out the spark plug wires to the rear Taurus cylinders. These should pull out gently, and you can replace or check the spark plug in cylinder #3.

Ford Taurus P0303 Trouble Code 26

Make sure to avoid dropping anything into the engine, as the lower intake manifold is open. After you replace the spark plugs in cylinder #3, you can check the spark plug wires for any damage. Replace all of the spark plugs in your 3.0 liter Duratec engine before re-installing your intake manifold.

To correct your Ford Taurus P0303 misfire code, you can also check the ignition coils using this guide here. This of course eliminates just one of the causes of engine misfire, the next step is to also check the fuel injectors on your Ford Taurus.

Have any questions about our Ford Taurus P0303 guide? Leave them for us below and let us know!

Submit Your Code