My dad'* 92 Park Avenue has had this problem for a while and now we are wondering. His car'* "Service Engine Soon light" is comming on and the car is giving Code 39 "Torque converter clutch circut" it only comes on when slowing down comming off the freeway when the car is in overdrive. But we have also noticed that his car has been getting really lousy gas mileage all of a sudden. Could this be the cause? Should it be corrected?

It sounds like the TCC is not engaging(in effect, No OD) so this would be one reason(there are possibly others) why your Dad'* PA is getting such bad gas mileage. I am not the transmission expert here(others will be on board later to help) but if the TCC is not locking up properly, it may cause the xmission to heat up and fail prematurely. So the first thing I would do is check the condition/level of the transmision fluid. That is, what color is the fluid? Red, Brown, Black???!!! You also mentioned that this problem has been going on "for awhile". This is NOT a good thing, avoiding what may have been a simple fix that may turn out to be a major expense to remedy.

Anybody know what parts should be replaced and if possible the part#'*

Ya know, with almost 200K on this vehicle just throwing in parts thinking that you're going to solve the OD issue is not the way to go here. If this is the original transmission any reputable transmission shop will recommend that you rebuild this xmission. Of course I'm assuming that this is the original transmission. If the rest of the car is in good shape you might want to invest a couple of bucks into it. But that'* a decision Dad will ultimately have to make.

My dad has decided to return the parts to the dealer and start looking for a new car. He found out that it is going to cost $400 labor to install the $15 part.