I have a 1997 ls 400 that is blowing ever so slightly cool air. I replaced the compressor and clutch, suction hose, discharge hose, condenser, drier, pressure switch, expansion tube. I cleaned all lines, replaced all o rings. I did not mess with the evaporator or the EPR that is located on the driver side firewall. I took it to an independent toyota mechanic and he evacuated the system and recharged it. It does not blow ice cold or even cold air.. I would compare it to a swamp cooler. Now, I have found very little on the EPR on the internet. My mechanic told me that I should replace the EPR valve which is 240.00 and I will spend the money if in fact it cures the problem but i have come across a few people in the business that say they have never seen an EPR fail? My mechanic also told me that it wouldn't be the first time that a brand new expansion valve has failed either. I installed the blower unit and the glove box back together and if I don't have to go back in there again it is fine by me. It is a very claustrophobic scary place to be and a lot of work. On the suction line where the EPR valve is, the suction hose is cold and condensating between the compressor and the EPR but from the EPR to the evaporator it is cool but not as cold. That doesn't make sense to me and that is why I suspect the EPR because why would it get colder past the EPR? As far as I have tested the blend doors are all working correctly. Could a bad EPR cause the expansion valve to not work correctly because the copper tube from the expansion valve fits into the EPR, which I was told is to prevent the evaporator to freeze up? Any help in this matter would be greatly appreciated. Thanks.

 

Take a look at this (I have not read it all the way thru)
http://us.lexusownersclub.com/forums...ure-regulator/

it may help you.

 

I just wanted to give an update to the problem that I was having with my A/C system. It was in fact the EPR, Evaporator Pressure Regulator. I changed it out and the pressure in the Low side went down to normal. The only thing that I can tell anybody with the EPR is that the low side hard line was cool to the touch but not cold before the EPR and it was real cold after the EPR to the compressor and the low side pressure was very high and the system was not blowing cold at all. I hope that this helps someone that is battling this same problem because there is not a lot of information on the web about it. Good luck!

 

Thanks for the update.

 

Hi,
have you replace EPR by yourself or your mechanic did for you?
I have LS400 same year, just need to know where is the EPR locate and how to remove it.
Thank you in advance.
Skippy.