So, I purchased a 2004 Hyundai Santa-Fe about a month ago with 120,000KM. Right off the bat I noticed that the shifts.. to me were a TAD rough, but that aside, specifically going into the last gear (3-4?) about half the time it seems to hesitate or very suddenly go into gear. This is not hugely noticeable but I have had a few cars with transmission problems and I want to nip this is the a$$.
I took it to my mechanic and had everything checked. He said the fluid looked good and he felt nothing on the test drive. Looking good and being good are very different things so I ended up taking it back and got the transmission flushed. (No filter done). And he thought it could be a computer error so he took out and put the battery back in (this was at the first visit, the flush was at the second visit).
SO the computer reset helped, and so did the flush, the problem is still there just not as frequent but it is still that same gear.
SO a week later the Check Engine light came on so I naturally thought, "great, now I know what the problem is, this is probally it", took it to Hyundai and it turns out it is a bad O2 sensor which I have yet to replace.

Has anyone ever had this before, or have a idea what it could be? I kind of think it might be a sensor, but having the computer scanned and showing no codes but the O2 makes me think otherwise. Like I said, I have had cars with transmission problems before, and this really does not feel like a mechanical problem.

Thanks in advance!

 

NOTE: Transmission was flushed with HYUNDAI FLUID, no aftermarket universal stuff.

 

hi friend I bought a santa fe new in 04 it is the four cylinder with automatic tranny. it has been just great .as far as your tranny shift mine has allways from new been just a little weird this meaning it sometimes takes a little while to shift to third or overdrive if it is cold out say teens to about 40 degrees But i was told this was normal till fluid heated a bit and was in trans shift program for it to do this' also you may note that when going at highway speeds when you let off the gas and then gently reapply it you will notice tac needle goes up a little then comes down a little .this is just overdrive taking back over and it is normal.my 04 santa fe has 136000 and still does just fine and i plan on keeping it a long time. hope this helps