Trac Off & Check Engine Light

[Guru_37]

After the check engine light came on and told us that we need new spark plugs, also evident from the mild shaking from the engine and misfiring. We replaced the spark plugs with new ones (Bosh Platinum +4).
From there, my dad was driving his 97 Toyota Avalon and the check engine light hasn't come off yet , but the car is running great now. As well, the car slipped a bit a stop sign when he pushed the throttle and the "Trac Off" came on, and it stayed on, even after we pressed the "Trac Off" button a couple of times.
What can we do to take off the "Trac Off" sign on the dashboard, also the "Check Engine Light."? - I know that the "Trac Off" means that the traction control is off.

[pasco]

you need to have the fault codes cleared. Once this is done, check engine and TRAC OFF light will go off. The button for TRAC will start working again.

Clearing codes can only be done using a scan tool. Go to Autozone or Murrays and they will do this free.

[tfeld]

You can clear the ECU codes by just disconnecting the battery for 10 minutes too. But before you do so, if you have a radio with security code, be sure you know the security code, 'cause you'll have to reset it.

[Joe W]

On cars newer than 1996, the only way to clear the codes is with a scan tool. Also there have been reports of the +4spark plugs triggering codes.