Misfiring after washing undercarriage

My '99 Limited had been running great. I'd been driving it on the beach a lot lately so this past weekend I decided to rinse off the undercarriage with the hose sprayer attached to a broom stick. Well I must have screwed up because now its misfiring really bad and feels like it's about to breakdown. I can hardly go over 35 mph. I was hoping that whatever I got wet would dry out overnight but it's actually worse today than yesterday. Any thoughts on what I did? Should the undercarriage not be rinsed off?

 

What code or cords are you getting off of OBD?

 

The undercarriage should be sprayed down, but when your working with pressurized water you have to be careful where you aim it. The electronics are designed to protect against splashes and maybe being submerged for a short time, but it wont protect against the directed water jet of a hose. Which is why many engine detailers will cover electrical components with plastic before spraying down the engine.

Where did you spray? There are lots of plugs and sensors around the underside. The O2 sensor is in the firing line if your doing an underside spray down, and it can certainly cause problems.

If you were spraying up towards the front of the frame, it's possible you were getting pressurized water all over the engine bay, and there are even more connectors there. I'd look at the codes if there are any for the misfire. I'd also pull any plugs you think might of gotten sprayed, clean them (not with water), and put them back.

 

Had the ignition coil and plug wires replaced, it's running great again.

 

Thanks for closing this thread