TOVRLND

My 2008 GX470 with 170k miles just had the dash light up like a christmas tree. Ill be scanning with OBDII scanner this evening when I get home. Just wanted to get this thread rolling (1st post) but i will update with what i find. Im hoping its the gas cap, which has been loose feeling for some time now. Any idea if this could also be the cause of my 1mpg fuel mileage drop?

waterca

This happened to me as well after I reset the maintenance light. That light went off and the others came on. Just bought it and lemon squad said all codes came back negative when they checked. An 08 as well. I disconnected the battery last week and they went off for awhile, but came back on yesterday.

chiph9

Replacing the gas cap is pretty cheap - like under $30, IIRC. Give it a couple of drive cycles after doing that to let any codes clear.

The other possibility is an old/weak battery. Do the cap first (cheaper), then have the battery tested.

Chip H.

01Snake

Just had this happen as well. As others have said, new gas cap, disconnected battery for 20 minutes and problem solved.

tz693

It happened to me three times and turned out to be O2 sensors (I have 3 out of 4 O2 sensors gone bad on my 04 so far). Scan the code to confirm.

01Snake

Oops. Should have added that as well. I checked my code as well and it showed P0420

TOVRLND

Thanks for the input. I should know more when I scan the codes, but the battery is over 110k miles old (5years+) and the cats and sensors are stock with 170k miles. So really any of these issues wouldn't surprise me. Still hoping for the fuel cap though lol

TOVRLND

Turns out it was the Fuel Cap. reset the codes and the codes cleared and havent come back.

radiant

chiph9

C1201 indicates ECU. P0442 indicates the gas cap.

An OEM gas cap is about $30.
The ECU is a couple thousand.

Replace the gas cap first, then disconnect the negative battery terminal for a couple of minutes to reset the computer. See if the codes return before spending more money.

Chip H.