2G Random misfire and flashing CEL

[98gstJames]

So I’ve been trying to get to the bottom of this issue and would like some opinions on it as well.

So I took my car home from our shop about a month and a half ago and on the way home it got a bad misfire sounding like it was only firing on two cylinders, I thought it’s the crappy iridium plugs that took a shit so I got the good NGK copper plugs and put em in. I thought it fixed my issue only the other day I was going to Walmart and it did it to me again and I was like WTF. Pulled in and turned the car off and let it sit while I got my groceries. Came out and the car started no issues and no longer had a misfire and didn’t do it to me again.

I do notice that even on the slightest pulls the CEL flashes indicating the misfire on multiple cylinders. I have brand new spark plug wires and spark plugs in the car, I’m on DSMLink and it all looks good and I have no other CELs on the car. I can take the car on quick drives no issues so I’m not getting this.

Could this be a possible faulty PTU that’s intermittently working? Possible ignition coils? The car drives fine even when the flashing happens I’ve just had it do the random two cylinder misfire to me twice and I don’t get it.

Thanks in advance.

 

[TerminalTalon]

It sounds like a PTU or coil considering your 2 cylinder description.

 

[chrisman287]

Check the wiring to your PTU. Give a light tug to each wire make sure none pull out. You can also test the PTU:

http://www.dsmtuners.com/threads/how-to-test-the-power-transistors.229419/

Check your ECU also. Open it up and check the capacitors. If everything above checks out it’s likely the coils but could be a wiring issue also.

 

[98gstJames]

So I went ahead and got a second PTU to test and it did it again so that leads me to believe it’s one of the coils just because I just recently got my ECU with DSMLink so the ECU is fresh.

How could I tell which coil is the culprit?

 

[chrysler kid]

You can use the factory service manual and a volt meter to test resistance of the coils

The factory service manual is online for free at www.charm.li

 

[Justin DuBois]

If your plug wires are done and over, arcing where they should not, you can also get the behavior you describe.