My 2007 GS350 has that often talked about smell coming from the a/c. I stopped into a local auto parts store and got a can of duct cleaner. In the instructions it says if it's possible to locate the recirculating air intake, spray some product in there too. I looked under the dash, but I only see the outlets for the air. Anybody know where this intake is? Thanks in advance.

 

its outside between the hood and windshield. look at the front cowl and you'll see grills or inlets around windshield wipers. you want to turn your heater/ac on full blast and start spraying the bottle at that location.

 

That's not the one. That's for when the system is on fresh air.
When it's on recirculate, the air inside the car is recirculated, so there has to be an intake inside the car.

 

Just put the car in recirculate mode, and open the access panel for the air filter behind the glovebox. Take the air filter out and spray right in there.

I don't know if those treatments can do anything if you already have a big smell problem though.

Keep the car out of recirculate mode for a long time and see if you can dry the system out completely. Hopefully it can stay dry enough for long enough to kill off any mold/bacteria but that will depend on how humid the climate is too.

 

South Florida. Humidity is a given.
I'll try the filter access. Thanks

 

When I did mine, I sprayed 1/2 can from outside. Then went inside the car and put it in recirculate mode then sprayed the remaining under the passenger footwell.

 

your method is not efficient. There's too much distance, and not enough suction, and there's usually some coarse filter (which you can't see unless you remove the cowl) that keeps the big particles out.
that filter will also block most of your spray.

better to remove the cabin filter door and set it to recirc.
this way, you have direct access to the fan motor, and it will blow everything deep into the ducts and evaporator.

 

I don't have enough experience with the Lexus because I just purchased mine. However, my last car had a horrible smell and it was because the cabin air filter started to mildew/mold. Once I replaced it, the smell was gone completely.

 

Be very careful to have the car in recirculate mode before removing the door to the cabin air filter. If you don't, you'll break the mechanism and it's a PIA and very expensive to replace.

 

If u put it in Recirc mode the gate thing will close, its pretty pointless there 2. Ill be honest i took the filter out and sprayed on the bottom of where the filter sits. Then turned on the heat and OHHH MAN all that alcohol from the spray came through vents it was nuts. Did it help? Yea for those 30 seconds while it was fresh.

 

Check to make sure the excess evap water is draining out the rubber tube when its running, sometimes the water gets trapped in the tray and rots/molds inside.

 

It sounds like you haven't tried this at all. You are just confusing the op.
I've tried this method multiple times on both Audi S4 and Lexus GS300 with success. S4 had pretty nasty moldy smell after each summer season.
There was a video clip instruction on how to clean evap core plus antimicrobial spray like the one we are talking about. I looked but I couldn't find it, but basically you have clean out every path of the air way from outside as well as recir from inside. I don't care how thick this exterior filter is but aerosole sprays will get through.