I made this account to post about this, sorry if I break any forum rules!

I haven’t seen much online about this so I wanted to share because it might be useful to somebody.

As many may now, the front passenger carpet of 1st gen crvs are susceptible to getting wet from the recirculating vent under the windshield cowl.

Recently my ECU/ECM (whatever the proper term is), was found to be the cause of my car acting up & misfiring. Upon further inspection, the plug that is furthest towards the back of the ECU was wet with an oily residue inside the connector. Also, the metal frame for the ECU, where the cord resided, had rust stains from what I assume was water.

I would guess that the water that used to be leaking through my recirculating vent was most likely trickling down this cord & eventually frying my ECU.

Here is the crazy part

I went to the junkyard to pull a replacement ECU. FIVE out of the six 1999-2001 Cr-vs had the exact same oily watery residue on the far plug. I believe this is a common reason for unsolved misfire problems and stalling, that is completely overlooked.

If you have fallen victim to your passenger carpet getting wet when it rains, I would love for you to check your ECU plugs to see if the ECU is wet, & report back here. I hope this helps someone!

sidenote: you can cover the recirculating vent if you pull your windshield cowl up, & block it with something, to prevent water from ever leaking through it again

 

I think you are talking about the fresh air vent. That's what is in the windshield cowl. When you choose recirc or Max AC what the HVAC does is close the fresh air vent that's in the cowl and open the recirculation vent that's under the dash and the blower just basically grabs air from inside the cabin pushes it through the heater core and the AC evaporator and does not pull in the outside air , AKA recirculation mode. If you block the air intake in the cowl you will cut off the fresh air inlet. There is a drain in the cowl and if it is plugged, the water will backup into the HVAC ductwork through the fresh air intake.

 

Yes thank you, I didn’t know the proper name for it. I didn’t block the vent entirely, I followed a YouTube video about folding a small piece of sheet metal over it to cover it, & it immediately stopped my carpet from getting soaked in the rain ever again. There’s still a considerable gap under the metal for airflow. But I believe this to be the cause of numerous 99-01 crvs getting water damaged ecus. The cord that gets wet runs right along the metal frame in a perfect fashion for water to run down it & directly into the connector.