the famous 300 , 6cyl
Just a couple of thoughts, This could be completely coincidental as it was just an ignition tune-up
1st . Try and unhook your battery for 2 mins and clear any stored trouble codes in ECM, as you said if comes on after N.O.T. (normal operating temp) and system runs closed loop so all sensors and controls are activated 2nd . Double check your new plugs for correct heat range, I have heard sometimes if range is off it could throw off your o2 sensor as the engine doesn't run effeciently or burn correctly. 3rd . Again might be coincidence that light is on, if your truck is running the same it's not a hard code and truck is not in "limp" mode running like crap.
if you plan on keeping your truck consider buying a code reader from a auto parts dealer, just a shot in the dark but hope it was of some help
Jason
Did you reset the light? I don't know what gasket you changed, but undoubtedly that was not the problem. The check engine light comes on when there is a problem with the emissions system.
changed battery engine light stays on
I have a 2003 Highlander. Whenever I get the oil changed, the check engine light comes on within a couple of days. I finally figured out that there is a hose under the air filter case that gets disconnected when the filter is checked. Just reattach the hose and the light will reset after a few restarts of the engine.
WHENEVER the check engine light comes on, ALWAYS connect a code scanner to figure out why. The light is on to tell you that the computer has detected a "fault" and it wants to tell you all about it.
why do check engine light comes on
yes, the engine fan need to b running whenever the engine is on the fan is to cool radiater, it only comes on when the engine gets to warm, to cool engine down.
oxygen sensor
Check engine lights come on for several reasons. I own a 98 Monte and my check engine light comes on alot. It could be any thing from a un clipped sensor, fuse, oil needs changed or checked. Take it to Pep Boys or Autozone they check out your check engine light for free.
There is another problem. see related questions.
The easiest way is to visit a local Murrays or Autozone. Either store will perform a free diagnostic and reset if asked. Its a free service and I use it whenever my "check engine" light comes on for any vehicle.
No, the check engine light comes on when the computer detects a malfunction and sets a code.No, the check engine light comes on when the computer detects a malfunction and sets a code.
The check engine light comes on at start up for a bulb check. If it stays on with the engine running the computer has detected a malfunction. You need to have it checked for codes.