hey scotty,, i bought a 2008 Lexus RX 350 with 211k miles on it engine and transmission smooth as butter,, only problem is after fixing the a/c the car started to do a slight idle drop and i thought it was the a/c compressor straining the engine,,

now when i turned off the a/c to see if it will still do it, i was wrong, it continued to do the idle drop.

Now I never replace the fuel injectors yet or the fuel pump I haven't replaced that as well,, &  the car didnt came with any maintenance history papers.

But what was done to the car though was a coil pack replacement, all sparkplugs and intake manifold seals the rubber seals,,

and some sawdering done to the coil pack wires to rewire some pigtail sensors that connects to the spark plug tube sensor.

But after doing all of that and adding freeant to the car is when the car started to do the idle drop thing it was doing.  

so my questions to you are if you know, does the car have a fuel filter built in somewhere on the gas tank outside?

or inside the gas tank? or on the fuel pump?

please see : I had to use lacquer thinner to make the car stop the idle drop thing but after I added the lacquer thinner I added 2 gallons of gas at a one gas station and it ran fine no problems at all.

Then when I added some gas from a other gas station about 1.5 gallons (less gas) it started to do the idle drop thing.

so I don't know if that means it has water in the gas at the gas station I took less gas from.