About 4 months ago my 06 TB StabiliTrak Indicator Light, check engine light, reduced engine power light started coming on at the same time. With this my TB power is reduced by about 1/2. I cannot figure out why this is happening. If I turn off the TB and remove and replace the gas cap everything but the check engine light goes off. The check engine light will eventually turn off if the TB is left off for a few hours. I have bought a new gas cap but this did not fix the issue. Everything will be okay for a few days up to a week later but then it happens again. Has anyone experianced this before. I have no codes to post because I cannot make it go into fault, it just happens when it wants to. Any assistance is welcome. Thanks in advance.