What causes engine misfires to stay after new plugs and coil packs?

#2 cylinder misfire. Plug, wire, or coil pack. One of them is bad. My guess is the coil pack. Pull the wire off the coil, lay it on top the coil close to the #2 port. Start the van. You should see the coil throwing an arc to the plug wire. No arc replace the coil. If you have arc, then replace the plug and wire. I would do all of them.

Cold starting misfires can often be caused by either tired high tension spark plug leads or ignition coil packs. If replacing leads, then replace with a full, new set. Coils can be changed individually, but it is often the case that if one has failed, then the others aren't far behind. Some cars have individual coil packs on each spark plug. Some cars have a single pack for all plugs and some have coil packs which may control two or more plugs.

To check for a misfire (ignition failure) follow these steps:

(Cold start) (Use a pair of insulated pliers)

1) Start the vehicle

2) When the vehicle starts misfiring, disconnect plug leads or coil pack connections one at a time. If the vehicle idles even more roughly, then that plug or pack should be considered fine.
Replug each connection before disconnecting the next one. Once you disconnect a plug lead or coil pack connection and find no difference in poor engine running, then you have likely found the offending cylinder. Check the spark plug condition, lead and/or coil condition and connections on that cylinder.

3) Replace components as necessary.

Hi there:
DTC P0300 - Random/Multiple Cylinder Misfire Detected



There are many issues that could cause this concern. Most common would be spark plugs and wires. A bad coil will also cause this issue. If this is the only code stored, it may be just that easy.


Other causes could be the engine is running lean, such as a vacuum leak in the intake. Also low fuel pressure or a injector that is dirty or going bad. A clogged catalytic converter may also cause a mis-fire condition.

A code P0300 may mean that one or more of the following has happened:

• Faulty spark plugs or wires
• Faulty coil (pack)
• Faulty oxygen sensor(s)
• Faulty fuel injector(s)
• Burned exhaust valve
• Faulty catalytic converter(s)
• Stuck/blocked EGR valve / passages
• Faulty camshaft position sensor
• Defective computer

Additionally, I would check all vacuum lines it is very common on this vehicle for there to be a vacuum leak, if none are found I would get the fuel injection system cleaned it is often the cause of a misfire.
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

PO 300 is multiple misfires detected
PO 301, 304, 305, 306 are misfires in cylinders 1,4,5,&6
PO 053 is HO2S Bank 1 Sensor 1 Heater Resistance
PO 106 is MAP/BARO CKT Range / Perf
PO 316 is Misfire detected 1st 1000 Revs.

On a misfire, I usually push towards the spark plugs, plug wires, and coil packs / distributor coil.
You have PO 106 and PO 053 that need to be inquired about at nearest AutoZone.
They can give you an idea as to what is the problem on these.

Did a MAP sensor **** out and cause all the misfires ?
Did a misfire cause the MAP sensor error?
You see what I'm saying ?...Something caused all the misfires...thinking MAP...but not that familiar with the function of the MAP.

Hope this helps...

First step is new plugs. It's possible that you have a fouled #1 plug. If that doesn't work, check spark wires (if the car is so equipped) or if it has direct coil-on-plug ignition, where each cylinder has a coil pack on top of the plug, swap the coil packs between cylinders 1 and 2. Clear the code, run the car, and rescan the computer. If the code moves to indicate cylinder 2 misfiring, then your coil pack needs to be replaced.

A flashing light means you're actively misfiring. Have the ECU scanned to find out which cylinder it is. Bad coil packs are common and there is a recall for them. Call a dealer with your VIN number and if yours qualifies, you'll get four new ones free. If not, buy a coil pack for each cylinder that is indicated as misfiring and replace them. They're $35 at AutoZone and about $160 at an Audi dealer.

A flashing check engine light is a critical indicator. That usually means that something went wrong that will damage the emission control system... and that is usually an ignition issue. First off, the OEM plug your car calls for is an NGK irridium... NOT BOSCH and not anything with more than 1 prong. Those NGKs are like 2 bucks and they are the proper plug. Make sure you have these plugs and make sure they are gapped to .028. Next, my suggestion is put all the new stuff on again. Drive it to autozone and have them delete all the codes. Drive it around until the check engine light comes on again, then immediately go back and read the codes. The ECU is smart enough to know which cylinder is misfiring. On these cars, I think they have three banks of two... meaning one "coil" inside the coil pack operates two of the cylinders. So if you get multiple misfires, it's the coil. If you get one misfire it's probably an individual plug wire or plug. Good luck.

TRY REPLACING THE CRANKSHAFT POSITION SENSOR..HAVE SEEN THESE CAUSE MISFIRES AND LOW VOLTAGE DTCS AS PCM THINKS VEHICLE IS NOT RUNNING..ALTERNATOR MAY NOT BE PUTTING OUT PROPERLY

The most common problem for a misfire and a flashing check engine light is the ignition coi on plug.
Each spark plug has its own coil pack. With a coil pack failing it will also cause a airflow code as the car will start to run rich. With the vehicle misfiring it can also inhibit the Cruise control but it will not necessarily bring on a gearbox fault. The most common cause of the gearbox fault light coming on as you describe is usually a weak battery.
I would replace the coil pack and have the battery tested.
Thanks and good luck
JPTCAT

You may have a coil pack going bad. They're on the front top of the engine - you'll see them if you follow the spark plug wires back. Do you have any codes from having the engine scanned? If you can get it scanned (AutoZone will do it free), post the codes up and we'll see which cylinder(s) are misfiring. From there, you can swap coilpacks around and see whether the misfires follow the packs or stay in the original cylinders. If they move, you have a bad coil pack or two. If they don't, since you've already changed plugs and wires, I'd see about having the injectors diagnosed to see if any of them are failing.