jchirch

Sorry if I'm posting in the wrong forum. New to Lexus, and to CL. I'm chasing down a couple of "too lean" codes, and thought to check the fuel filter. Can't find any reference to fuel filters here. What am I missing?
Thanks for any help--including help w/ navigating the forums.

JC - 2007 is250 AWD

MikeFig82

iTrader: (13)

It's in the fuel pump assembly. You'd have to remove the whole module and disassemble to get to it.

jchirch

Thanks for the info. I assume that the fuel pressure sensor will tell me when it's time to tear into the fuel pump.

Viru

Question on this note - what's the replacement interval for the fuel filter? Does the tank need to be dropped to swap it out?

MikeFig82

iTrader: (13)

The tank doesn't need to be dropped. Take out the back lower seat cushion. You'll see the screws for the module on the gas tank. There is no interval according to Lexus. See link below it helped me decide on my GS400. Since I don't know if the previous owner had changed it or not.

Use this link for reference. Though use extreme caution you'll be dealing with fuel.

https://www.clublexus.com/forums/gs-2nd-gen-1998-2005/483026-cross-section-of-gs-fuel-filter.html

timmy0tool

iTrader: (7)

what codes are you seeing exactly? too lean could also mean your o2 sensors are not reading properly.
you might be chasing the wrong problem.

jchirch

Codes are P0171 & P0174, system too lean bank 1, system too lean, bank 2. My thinking is that the likelihood of both upstream o2 sensors failing at exactly the same time, in the same manner, is very low. i.e., they're probably still functioning. Thus, there's too much air, or too little fuel in the system when these codes are thrown. Haven't been able to find any intake leaks (tho I haven't done a smoke test yet), so if the fuel filter is really there & not just a sock-type, I might take a look at it.

whitebeast

iTrader: (5)

MikeFig82

iTrader: (13)

Check MAF, Vac Lines, Start the car and pay attention to any hissing noises. If it's a large leak it will be hissing like crazy. then proceeded to the next steps.

There's a ton of info on this subject online.

2013FSport

iTrader: (2)

I vote MAF too....
If that doesn't change it, let us know from engine running to engine off; how many times can you pump the brake pedal before you loose vacuum assist?

PS the cardboard tube from a roll of paper towels works great as a directional aid. Put to your ear and it allows you to focus on where the sounds are coming from.

svnsales

Just over a year after my original question, hit 150k miles and replaced my filter! Took about an hour start to finish. A lot more finicky than an inline filter, but super doable if you take your time. Note: I couldn't find a new fuel strainer locally, so ended up cleaning the old one out with starting fluid. Main filter is a new Beck/Arnley unit off RockAuto.


The pump assembly lives under this cover

The pump assembly (ignore my messy truck tailgate)

With the old filter out - ready to transfer the motor/strainer unit to the new filter.

Cleaned strainer

Old vs new filter - you can see how dirty the old media is, through the holes.

MikeFig82

iTrader: (13)

Adding this here also:

https://www.clublexus.com/forums/is-...el-filter.html