im having a problem with my car it keeps throwing the p0121 code. i thought it was the tps sensor so wat i did was bought a brand new tps from the dealer. the check engine went away for like 2 hours then i raced the car and bam!!! it came back. do you have any suggestions on wat i should do??? if i clear the code its fine. i just did a pull on the freeway and 1st, 2nd, 3rd, 4th gear are fine at wide open throttle. as soon as i shift into 5th the check engine light comes on and it says p0121.