My 2000 lincoln ls has check engine light on with codes p0303 and p0301 I have replaced the plugs and coils on # 1 and 3 cylinders but no help . the car is running very rough

Change the coil pack from cylinder 3 to cylinder 1. If you get a code p0301 after the swap, then that coil pack is bad, replace it. If you still get a p0303, then check the wiring to coil pack 3. If you have a combination coil pack, then replace the whole unit.

First you need to retrieve codes from the Engine control module. You can buy a cheap code retriever at harbor freight and get the codes. After you get the codes, if it is P0301 it means cyl #1, P0302 = cyl #2, P0303=cyl 3 and P0304= cyl 4. For ex: if you got P0301 you should remove the ignition coil #1(near the front of the engine, where the pulley is) and change its position with the coil # 2. Also remove the spark plug #1 and change the position with the spark plug #4. Clear the codes and start and run the engine until the check engine light goes on. Check for codes and see if the code change for a different code. If it change the position observe which one is the change. If is P0304 you have a bad spark plug, If it is P0302 you have a bad coil. If it repeat P0301, you have either a low compression, bad injector/connector, bad intake gasket them you should continue your diagnostic. I hope this help you.
Junior.

you have multiple cylinder missfire 1,2,3,5 check your spark plugs, plug wires and coils could even be a o2 sensor

P0301 Code - Cylinder #1 Misfire
A P0301 code means that the the car's computer has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #1.

Symptoms may include:
- the engine may be harder to start
- the engine may stumble / stumble, and/or hesitate, other symptoms may also be present.

A code P0301 may mean that one or more of the following has happened:
- Faulty spark plug or wire
- Faulty coil (pack)
- Faulty oxygen sensor(s)
- Faulty fuel injector
- Burned exhaust valve
- Faulty catalytic converter(s)
- Running out of fuel
- Poor compression
- Defective computer

* This conditions is the same when code is P0302 or P0303.

Possible Solutions:
If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using FixYa, have a nice day.

Hi John:
P0301 Code - Cylinder #1 Misfire
A P0301 code means that the the car's computer has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #1.

Symptoms may include:
- the engine may be harder to start
- the engine may stumble / stumble, and/or hesitate, other symptoms may also be present.

A code P0301 may mean that one or more of the following has happened:
- Faulty spark plug or wire
- Faulty coil (pack)
- Faulty oxygen sensor(s)
- Faulty fuel injector
- Burned exhaust valve
- Faulty catalytic converter(s)
- Running out of fuel
- Poor compression
- Defective computer

* This conditions is the same when code is P0302 or P0303.

Possible Solutions:
If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using FixYa, have a nice day.

P1354VVT System Malfunction (Bank 2)

• P0300 Random/Multiple Cylinder Misfire Detected
• P0301 Cylinder 1 Misfire Detected
• P0302 Cylinder 2 Misfire Detected
• P0303 Cylinder 3 Misfire Detected
• P0304 Cylinder 4 Misfire Detected
• P0305 Cylinder 5 Misfire Detected
• P0306 Cylinder 6 Misfire Detected
• P0307 Cylinder 7 Misfire Detected
• P0308 Cylinder 8 Misfire Detected

Probably bad plug wires. Start there and then disconnect the battery for 5 minutes reconnect and start engine to see which codes have cleared.

You are exactly right it is bad plug or coil on that cylinder!!

Cylinder 3 Misfire Detected is a P0303

The MAF sensor is not the problem, these are cylinder misfires on #1,3 and 4. replace the #4 coil pack, #1 AND 4 use the same coil, replace the spark plugs and the wires.

Hello I need a help.
I have 1999 lincoln town car 4.6L V8.They have check engine light on. P 0303 cylinder 3 missfire.
I was changed spark plugs,fuel filter. check compression test 150psi. fuel pressuer 50.
swiching cylinder 1 to 3 fuel injector and coil. but they still have engine code