Ok... So my girl has a 2006 Scion TC with about 55,000 miles on it. Car is pretty much bone stock as far as engine and all that.. Only mods on the car is a system and hid's... Well anyway.. She had a check engine light come on and i checked the obvious first and found that the gas cap was left loose and barely on.. So i told her to drive around and it should turn off by itself.. She came to me like a day later and said it didnt turn off and that it was "bothering" her that it was on.. i told her that i could disconnect the battery and wipe the code out but advised she should get the code checked, just in case.. she opted not to spend the money to have it checked so i disconnected the battery and let it sit.. when i reconnected the battery i went to start the car and it turned over but didnt fully start.. i thought maybe i just didnt hold the key long enough and went to start again.. this time it started up but ran rough and the car was vibrating a lot.. it was getting late so i figured it probably just needed to run.. so the next morning she let the car run for a bout 25 minutes and took off for work.. she said the car was still vibrating and then stalled out around the corner.. she said it started right back up but was running rough.. i had it towed back to the house and started the car with the spare key.. i got minor vibrations at first but then smoothed out after giving some gas and letting it run.. took it for a drive and everything "seemed" ok.. just wondering what may have caused this problem and what i should look at.. no codes or lights or anything as of now.. thanks for any input and sorry for the long post..

 

1. don't pay to get codes checked as autozone and o'reilly's check those for free
2. check to make sure battery cables to make sure they are on firmly as if they are loose, they can lose connection and cause it to not start/stall, ect...
and the vibration i'm not to sure about.

 

if you wiped the cars memory by disconnecting the battery, it can run funny for a bit, but sounds like the ground is loose, do a hard reset. ( take the negative terminal off the battery and touch it to the positive terminal while its still connected)

then replace them make sure they are tight and secure, and see if it runs better

 

try the hard reset like Blue TC Man says but check to see if the audio system has a 1/2 farad or 1 farad capacitor in it... those caps usually have enough juice in them to keep the code from getting wiped out... disconnect the cap and the main battery and try again... the ECU should reset at that point and it will run a lil rough at first as the computer picks up all of the sensors information...

 

Dear God do not touch the neg cable to the pos cable.......it will not end pretty for you.....just take off neg cable for a few minutes,put back on,start car let idle a few mnutes,then take amellow drive once the idle RPMs drop and car will relearn what it is doing....and run properly,if code comes back after that goto autozone and have code checked for what it is and let us know......