Fuel filter keeps getting clogged

Hi all - I have an '01 Tacoma V6 ext. cab 4x4 and I had my fuel filter replaced in early Jan. and now, not more 3k miles later, the engine is running rough again and it just popped a P0171 'System Too Lean' code. So I'll be replacing the filter again this week. Has anyone had issues like this? How can it be clogging so often? One theory I have is that before I had the filter replaced the first time I ran a bottle of injection cleaner through the truck thinking it was in need of cleaning, so maybe that released a bunch of gunk in the tank and it's just working its way through?

thanks for you help!

 

P0171 can be several things...most commonly a vacuum leak or issue with the MAF sensor. If your fuel filter is brand new I wouldn't suspect that to be the problem...what brand did you go with? They're pretty cheap and easy to replace (on the V6) so maybe just do it to see if it solves the problem, if not then I'd start checking over your vacuum lines for leaks

 

Theres a sock at the bottom of the fuel pump, they can degrade and send chunks into the pump and end up in the filter. Might be a good idea to drop the tank and peek inside to see the condition of the sock and the tank itself.

 

I was thinking same. Drop and check tank. Flush it while you got it down then that would eliminate that end.

 

after the really cold weather this January, I had a vibration at idle and just recently the odd time, a really rough idle at a stop light. Smooth acceleration otherwise. Toyota scanned it and there was aa P160500 rough idle code which they cleared, but they had no suggestion as to the reason for it.

 

Thanks all - I'll talk to the mechanic about that. I'm going to try the filter first and see if it goes away. Is checking for vacuum leaks easy to do? I peaked at the diagram and it looks like it would be involved. Assuming they're all mostly visible by just opening the hood? I apologize, I've spent very little time working on the truck....

 

There are a bunch of evap hoses under the bed that connect to the gas tank. Depending on how rusty your tank is, the vacuum leak could be the sending gasket on the tank.

 

Was your first one actually clogged? I feel like the more likely situation is that disconnecting the battery when replacing the fuel filter the first time reset the code and it just took a while to come back. I would check the easy/usual suspects here like vac hoses, dirty or lazy maf, iac, cracked exhaust manifold… before messing with fuel

 

Pop the hood and look for any hoses that might be disconnected or brittle and starting to tear apart...it's very common on these older, higher mileage trucks. If you search P0171 on this forum it's probably one of the most common codes that comes up. Age/mileage do a number on rubber hoses, bushings, etc over time

If nothing is obviously disconnected you can try the starter fluid trick where you spray it around vacuum line connections and see if the RPMs go up...if they do then you've found a leak.

 

A clogged fuel filter will initially present as a loss of power at higher RPMs. IE more fuel required than it can flow. So, noticing loss of ability to maintain highway speeds is the most common customer complaint.

Fuel filters clogged rarely get to the point of rough idle or low speed problems, because they are found and dealt with sooner.

As others mentioned, a 'lean' code is not a direct correlation to a fuel filter issue. Several things can create lean conditions. Including too much air or too little fuel. Too much air can come from those mentioned vacuum leaks.

Start hunting there first.

 

Thanks for all the help with this guys!!!

It actually started with loss of power and 'bucking' when starting out. These were the same symptoms I had last time and then the filter change fixed it and the code stayed cleared. The same symptoms happened again this morning and the code reappeared. I'll replace the filter and buy an extra in case there is some gunk working it's way out of the tank. Hoping it's not a vacuum issue :-/

Also, the MAF was cleaned 2 months ago so its probably fine.

 

I'll try this too - thx!!

 

If the symptoms only happen when the code is around, it seems like the issue would be in the data that the fuel management system is using. Such as maf, ait, egt/ a/f, tps data or iac control.

also check out the vac hose that controls your fuel pressure regulator.

 

One more thing to note - I had the timing changed last week - are there any vacuum hoses that need to be disconnected and reconnected when this is done? I assume there probably is...

 

I would pull the filter and check if it's actually clogged first. Dropping the tank is a PITA, and if the filter isn't clogged it's kind of a pointless exercise, IMO.

If your filter is clogged (again), don't just keep replacing filters, there's no telling how much crap is in there and how many filters you're going to go through. That's when you drop the tank and clean it out. As @mlcc said, if that's happening, that sock on the pump is likely bad, and would need to be replaced anyway.

 

You mean the timing belt, yes?

I can't remember specifically which vacuum lines end up disconnected (if any), but that's a good possibility you'd end up with some disconnected.

The starter fluid trick is a good way to find vacuum leaks, but it sounds like you had a shop do the work so hopefully they're competent enough to do it right.

 

That pic looks like a den of vipers...

 

Poor quality gas??

Do you buy the same place all the time?

If the filter is indeed getting blocked.

 

OP, did you ever resolve this issue?