Check engine light
I recently bought a 2002 millenium. I am aware of potential problems. Two days ago, the 'check engine light' came on. At a mechanic shop, two codes showed up- one for a misfire on a cylinder (needing tune-up) and the second related to the EGR sensor. I plan to do a tune-up and clean the sensor instead of replacing (if possible). Here is my question. Last night, the 'check engine light' did not light up. I did add new gas to the tank and did tighten the gas cap. Any suggestions why the light went off!
Coil Misfires usually will be intermitent. They come and go, and the one coil that is faulty should be replaced sooner than later. Usually when one fails, others follow, so people usually will replace all and the plugs at one time. The EGR can be cleaned of carbon in some cases, but I would have your mechanic clear the codes after the coil change to see if the EGR comes back. Adding gas to the tank might have nothing to do with the light.
Tom is correct. Also, when an intermittent problem stops for awhile the computer (PCM) turns off the check engine light. The codes are still stored and the problem(s) still need to be addressed. I'd do the tune-up, clear the computer (PCM), and see if the light comes on again. If, after a week or so, the light stays off, you'll be good to go. HTH. -Jim
ive also found out too ...if that gas cap is not turned atleast 3 times my check engine light will come on. once it is tightened right it takes about 20 to 30 miles for the light to go off
There's a pressure sensor inside the gas tank. This is for the EVAP system. The EVAP system "recycles" gasoline fumes back to the engine to be burned instead of being released into the air. When your gas cap is loose the system doesn't build the proper pressure & the computer (PCM) sets a trouble code. -Jim