Lexus RX EGR Valve Issue

Smoke and hissing? Sounds bad. EGR valve problems usually just cause rough idling and maybe a check engine light. Are you sure it's not something more serious, like a vacuum leak or a blown head gasket? Have you checked for any obvious leaks or weird smells?

Didn't notice coolant leaks or sweet smells indicating head gasket. Hissing might be EGR valve gasket? Concerned about reduced power and smoke. Could a faulty EGR really cause those issues?

Okay, the smoke does point to the EGR valve possibly being stuck open, dumping too much exhaust back into the intake. Definitely get it checked out by a shop. Driving it like that could damage your catalytic converter. They can diagnose the EGR valve and confirm if that's the culprit. Better safe than sorry, especially with emissions stuff.

Took it to a mechanic, and you were right – it was the EGR valve. They replaced it for 355€. Runs like new now!