Ok i finally got my 3rd and 4th gear pressure sensors in and installed them on my car. The first time i installed them i did it backwards, i put 3rd in 4th spot and 4th in 3rd. After doing this the trans seemed to shit great smooth in every gear. I realized that i had them in backwards after looking and reading more on here so i went home that night after i put them in and reversed them again to put them in their correct position. After doing this i took it for a test drive and it shifts like it did before i changed the sensors, hard shifting into 4th under light acceleration. What will it hurt to run them the other way. That would be the 27lbs sensor (28600-P7W-003) the third gear spot and the 33lbs sensor (28600-P7Z-003) the fourth gear spot.

The car is a 05 acura tl base with nav.

 

Who told you to get those parts?

You need:
28610-RAY-003 (3rd)
28600-RAY-003 (4th)

 

 

the sensors that i have are the newest version of the ones you listed.

the real question is, will it hurt to run them in reverse of what they are supposed to be.
the car seems to shift much smoother when they are in backwards.

 

smoother isnt necessarily better. if anything it causes more wear.

 

That is an interesting question and the answer is complex.

To give you an answer one would need to measure 2nd, 3rd, 4th and 5th clutch pressure circuits under various shift conditions, any answer you get here will likely be opinions and thoughts.

Something to keep in mind is the release (or bleed down) pressure of these switches, that is part of the timing specification for a working switch. Changing the switches around affects all gears from 2nd to 5th. That hard shift into 4th is of concern and the fact that changing the switches around could point to a pressure/timing issue in either 3rd (release) of 4th clutch circuits.

I would definitely suggest NOT putting a 3rd gear P-switch in 4th.

I know this is not part of your question, however for the sake of pondering/thinking out loud - I don't know what problems you could end up having if you ran another 4th P-switch in place of 3rd P-switch. You may still have the same harsh shift? The problem as I see it though is the low 17 PSI release pressure, and exactly how the TCU uses 3rd clutch circuit low pressure release indication when timing clutch engagement/overlaps.

Not the answer you wanted I guess.