I'm in MD and we've been getting pretty consistent rain for the past few days... Expy was running fine until about 15 mins after a water crossing... Had to cross a flooded road that was about a foot deep.

So after about 15 mins after the crossing, I start feeling a miss (No check engine light) as I kept driving it steadily got worse. Just before I got home, I got the check engine light, which showed P0302 and P0304.

based on misfires on only 2 cylinders, I'm guessing it's not water in my fuel but water caused the COP to go bad or something similar.

Can someone tell me what the cylinder order numbers are so I can look? Is there anything specific I should look for? I saw some posts about water in the well and to blow dry it out. Could it just be water in the plug well and I can blow it out with compressed air? If it's water that got into the plug wells, what I can do, so it doesn't happen in the future?


Thanks!!

 

1-4 front to back on the passenger side, and 5-8 front to back on the driver's side.

Yes, most likely you got water down in the spark plug wells, and yes blowing them out with compressed air can help a lot.

 

There have been severl posts about this problem in the past and some have posted that they found that water was dripping off of cables or hoses onto the COPs, possibly from a poor or broken seal at the hood and cowl. If memory serves, they found a way to shield the COPs from this dripping and had no further problem with it.