Why is Toyota Sequoia won't idle after battery replacement?

Answer 1

My wife's 2002 Toyota Sequoia idle was poor after replacing the battery. Nothing seemed to fix the problem. I replaced the fuel filter. I drove around the block. No change.

My brother hooked up my Sequoia to his new computer software and no faulty codes showed up. It said my car had no problems and that everything was running fine. Except it would not idle.

I did a little homework on toyotanation.com, and found some important information. As you drive your car, hundreds of sensors adjust to your style of driving, humidity, altitude, etc. Weeks after you drive the car, the engine calibrates to its surroundings for maximum efficiency. If one of the sensors fails, you get a "check engine light" on the dash.

When your battery dies for a certain period of time, all your car's self calibration is lost.

When you put in a new battery, the computer and sensors fire back up and they all go back to pre-set factory "zero". The engine has a hard time idling because it needs to re-adjust for something in you engine: dirt around the air intake flap.

I removed the black rubber intake and revealed the opening of aluminum intake into the engine. With the engine off, I used carb cleaner and a rag and removed all the dark dirt build up around the throttle flap and surrounding area. I used a screwdriver to hold the flap open as I cleaned up and around the round hole and flap.

Three good individual starts of the engine and a few moments of sputtering.... the engine ran perfect like before.

The soot causes the engine to run poorly because the sensors have not modified to compensate for the old soot. Remove the soot, and everything is back to normal. Clean intake, clean factory settings of the sensors.... Normal running car.

Within the next few weeks, your car will re-calibrate itself for maximum efficiency based on the way you drive, elevation and other small factors.

I hope my experience helps you out and keeps you from spending a fortune at the dealer.