check engine light on 1999 Dodge Ram 1500

ok so i went to see why my check engine light was on they did a smoke test checked fillters and oxygen sensors and as well the gas cap and was good but did not find any thing when disconectting the battrey the light will go of for about a week then comes back on what would be the problem?

Asked by for the 1999 Dodge Ram 1500
I had the same problem. My gas cap was checked as good as well as all of your other items, Then the man tightened the gas cap real real tight and it went off forever!!!
Try that.
hey it worked awsome thanks
2 more answers , 5 more comments
Do you know the diagnostic trouble codes that they pull out from the ECM??

they said nothing showed up on there code system
If the check engine light was on there must have been least one code in the ECM.

they just told me they couldent find anything and no codes showed up showing why its on
Take it to another shop to see what code is stored? Most computer have a PROM chip that stores memory regardless if you disconnect the battery or not? If a code is still not present you may have a shorted wire from the computer to dash or a bad dash module? They may need to check the BCM to see if a code is stored there? This is a computer that is separate from the PCM. The BCM is also call the Body Control Module.
I agree with c & a automotive, take it to another shop and get a second opinion.

i figured out what it was it was a timing shifter sensor in the trans mission went out i got it fixed