this problem just showed up after a big rain storm that's been going on a couple days now. Car had standing water in passengers front and rear floor board so I got it all out and let it dry well it rained last night now the front passengers is damp and water standing in rear passenger. any idea where to start looking all the edges are dry and show no indication of a path where it came in. anyone else had this problem only thing ive done was run my nitrous line thru the grommet behind the pcm to the engine bay would it be building up there and coming in??? TIA

 

that wud be the most obvious problem. i ran my wiring thru there, and im in fear of water now, pain in the *** to seal up down there after u mess with the factory grommet. id bet money its running in there, and draining all the way to the back floor pan too

 

Look at the weather stripping around the door. There are channels that run from where the window seals up against the sail panel that sends water inside the tube of weather stripping then drains out of a hole at the bottom of the door. I had the same problem and I found a slit in the weatherstripping where all the water was coming out into the car instead of draining under the door and outside.

At least after I fixed that it stopped leaking, but I never parked on a really steep uphill again haha.

 

Get some empty gallon jugs of water or a garden hose and try to simulate rainfall in select areas. This should be able to help you determine whether the culprit is a void in the grommet or a failed door seal.

 

Hire a smoke machine and see where smoke comes out= water comes in.