The Check Engine Light may illuminate because a component of the oxygen sensor stops working. As a result the engine computer is unable to determine the proper ratio of air to fuel for the engine. Replacing the failed oxygen sensor should correct this concern.
Resources for the Repair and Maintenance of your 1999 Lexus ES300
1999 Lexus ES300
1999 Lexus ES300 Problems
On higher mileage vehicles, an engine misfire may develop and/or the Check Engine Light may illuminate due to a failed ignition coil. It is not uncommon to replace all the coils when the first one fails in order to prevent return trips to the repair shop.
Sludge can build up in the engine because Lexus did not recommend frequent enough oil changes. Lexus will sometimes offer a discount on cleaning the engine if necessary. Owners who changed their oil every 3,000 miles did not experience these problems. This sludge build up can lead to excessive oil consumption.
Intermittent failure of a purge control valve in the evaporative emission system can cause the Check Engine Light to illuminate. A failed valve should be replaced to correct this problem.
The Check Engine Light may illuminate because the mass air flow sensor sends incorrect information to the engine control computer. This can cause a loss of power on acceleration. A failed mass air flow sensor will require replacement.
1999 Lexus ES300 Questions and Answers
Car seems to bottom out with normal passenger load in rear. What is the problem? Car has 80000 miles.
#4 COIL WAS REPLACED TO ELIMINATE A MISFIRE, & LASTED 2 WEEKS, UNTIL THE MISFIRE RETURNED. REPLACING THE ECU FIXED IT PERMENANTLY.
CAN A FAULTY IGNITION COIL DAMAGE THE PCM COMPUTER?
My "check engine light" has been on for a week now. The dealer said the Catalytic coverter needs to be replaced, but they charge $2500 for a complete exhaust system; but...
I have replaced all the burned out bulbs necessary.When I turn the headlamps\running lamps on the dash light comes on.ALL bulbs work.What's Up?