What is wrong with the engine in my 2002 Honda Integra?

Engines like the Honda four-cylinder have lots and lots of electronic sensors scattered around the engine bay to keep them running sweetly and efficiently. High-pressure water can definitely get into places it shouldn’t be and send things haywire. Next time you get the engine up to temperature, park the car somewhere dry and leave the bonnet open to see if whatever is wet will dry out naturally.

Of course, that’s dependent on the burning-plastic smell not being something that’s about to catch fire. In fact, this is the more serious problem as a small piece of trim or soundproofing could also have moved during the high-pressure washing process and could be touching a hot component such as the exhaust system. If that’s the case, it can easily catch fire with predictable results. I would definitely be having somebody who knows what they’re looking at take a look to identify the source of the smell. Keep a fire extinguisher handy while you’re doing so, too.