Hi all, just wondering if any of you have had this occur to you. We have a 2002 MPV, and while driving in a heavy rain last night, it started shuddering, and the check engine light came on. I read the code and got a P0300 multiple, random misfires. I cleared the code, and when it dried out outside, took it for a drive- no problem. Drove it on a nice day today- no problem. Any ideas??? Thanks!

 

In my experience, those random wet-weather misfires are usually related to the ignition coils. There's one on each spark plug cable and rain and high humidity can cause them to fail intermittently, resulting in engine hiccups. It's a known issue and you can see many posts about it. You can usually trace it to the cylinder that's misfiring with an obd code reader, and then replace that coil. I bought a pack of 6 of them with good reviews on Amazon for $35. They're as much as $100 apiece if you get them from the dealer, or $35 apiece from auto part stores. If it's a coil on the front side of the engine, the coil replacement is easy. If it's the rear, you'll have to follow the tutorials because it involved removing the intake manifold to access the back cylinders. I replaced the 3 rear coils (because that's where my initial problem was) but within a year I had to replace the front cylinder coils, too, as they began to misfire.

 

Thank you for your feedback and the lead on the inexpensive coil packs. It hasn't had a problem since that night, but it will be good to have that info in my hip pocket in case it occurs again!