When changing the air filter, it is easy to knock off a hose on the air filter housing, which is part of the emission control system. If the vehicle is driven with this hose disconnected, the Check Engine Light will illuminate.
Car Problem Reports
Lexus ES300 Check Engine Light Due to Hose Off of Air Filter Housing
Lexus ES300 Problem
Engine Affected: 3.0L V6
Visitor, 2002 Lexus ES300, 3.0L V6, 208,000 mi
I took my car to the dealer for an oil and filter change. Within a few days, my check engine light came on, and I took it to the place who did the prior smog check. They lifted the hood and showed me that the nub where a hose connects to the front of the air filter housing was broken off in the hose; the hose was disconnected. I took the car back to the dealer, who epoxied the nub back onto the housing. This repair lasted a few days, and I noticed the hose was again off and the nub was in it. The dealer ordered a new air filter housing, and I am waiting for it to come in to be installed.