All of you have offered suggestions in regards to my 1998 SE/V6 with the auto transmission. I just got it back from a very reputable transmission shop and they replaced the "gear selector sensor". This was the code the transmssion was giving out. They also said that the temperature coolant sensor for the transmission needs to be replaced as well. They do not do this since it is not transmission work, rather a sensor located underneath the hood. They said the computer cannot tell how warm/cold the transmission is. The car contimues to "slip" sometimes between 3rd and 4th. Can anyone give me a part number for this? Could I replace it myself? And where is it located?