P0174 AND P0171 Same Time

[BigMike18]

I got both of these codes and the freeze frame for the data shows my long term fuel trims being above 25% (05 Limited 4WD V8). I cleaned the MAF sensor, nothing. Numbers go down as I accelerate

Im leaning towards a vacuum leak, but have no idea where to look for them besides the PCV valve, which just so happens that hose coming from it is pretty "busted up" and kinda cracked. Any ideas?

also seems to be effecting the good ole MPG's quite a bit

 

[81runner]

Pcvs are cheap, I say throw one in and see what happens. Vacuum lines are cheap too, shouldn't take much to replace. If you're trying to track down a vacuum leak, a nice trick is spray the line connections or any suspected leak site with brake cleaner while the engine runs. If it is leaking in that spot you'll hear the engine rev up when you spray. Consider the laundry list of parts that can cause this, I'd start with cheap and easy and go from there.

 

[BigMike18]

Pcvs are cheap, I say throw one in and see what happens. Vacuum lines are cheap too, shouldn't take much to replace. If you're trying to track down a vacuum leak, a nice trick is spray the line connections or any suspected leak site with brake cleaner while the engine runs. If it is leaking in that spot you'll hear the engine rev up when you spray. Consider the laundry list of parts that can cause this, I'd start with cheap and easy and go from there.

How do I know which lines are specifically Vacuum ones that I should be spraying, or just spray down anything? Thanks

 

[81runner]

Vacuum lines are usually pretty small. There's a few on the intake manifold, and a couple others spread throughout the engine. Vacuum lines usually don't have clamps on them, the rely on suction and the rubber hose to seal.

 

[BigMike18]

Vacuum lines are usually pretty small. There's a few on the intake manifold, and a couple others spread throughout the engine. Vacuum lines usually don't have clamps on them, the rely on suction and the rubber hose to seal.

Monitored today. Trims were 22% & 18%. Just starting car in Charlotte NC and rpms are blasted to 1300. Does this solidify my thought of vacuum leak?

 

[earthrealm]

my trims are 38% for LTFT2 & 19% for LTFT1, changed fuel tank cover, and bank 2 post cat oxygen sensor, no dice. my error code is p0174. next stop is the fuel pump, bought a fuel rail pressure test kit on amazon, but doesnt have all the connectors to test the v6 05 runner

 

[BigMike18]

my trims are 38% for LTFT2 & 19% for LTFT1, changed fuel tank cover, and bank 2 post cat oxygen sensor, no dice. my error code is p0174. next stop is the fuel pump, bought a fuel rail pressure test kit on amazon, but doesnt have all the connectors to test the v6 05 runner

Tried MAF sensor?

 

[81runner]

Monitored today. Trims were 22% & 18%. Just starting car in Charlotte NC and rpms are blasted to 1300. Does this solidify my thought of vacuum leak?

Not necessarily. Could still be anything. Vacuum leak is still the easiest to check. Is your exhaust rich smelling? The code means the engine THINKS it is running lean. Could be from loss of fuel pressure, or could be sucking air via a vacuum leak. Vacuum is the simplest thing to check for.

 

[81runner]

my trims are 38% for LTFT2 & 19% for LTFT1, changed fuel tank cover, and bank 2 post cat oxygen sensor, no dice. my error code is p0174. next stop is the fuel pump, bought a fuel rail pressure test kit on amazon, but doesnt have all the connectors to test the v6 05 runner

Have you done anything to the fuel rail yet? Regulator, injectors? Both trims are still high, not just bank 2.

 

[BigMike18]

Not necessarily. Could still be anything. Vacuum leak is still the easiest to check. Is your exhaust rich smelling? The code means the engine THINKS it is running lean. Could be from loss of fuel pressure, or could be sucking air via a vacuum leak. Vacuum is the simplest thing to check for.

Yes when I leave the rear window open, you can really smell it from the spoiler kinda sucking it back into the car. Going to get it checked sometime this week from local place.

 

[earthrealm]

Tried MAF sensor?

yup, cleaned that and TB, no dice. seems i would go right ahead and drop the tank, swap out the fuel pump+filter, arrgghh

 

[earthrealm]

Have you done anything to the fuel rail yet? Regulator, injectors? Both trims are still high, not just bank 2.

am fixing to simply replace the pump+filter, though i wish i was able to test the fuel pressure, checked a pals runner, he has 5% & 10% for bank 1 and 2 LT

 

[JRSC1]

Had same issue on my ‘05 V8 SR5. Replaced MAF after cleaning several times and still getting codes. Took it to Toyota Techs in Fort Mill and she had a cracked manifold.

 

[BigMike18]

Had same issue on my ‘05 V8 SR5. Replaced MAF after cleaning several times and still getting codes. Took it to Toyota Techs in Fort Mill and she had a cracked manifold.

Im in Fort Mil aswell, might go try that out

 

[earthrealm]

Had same issue on my ‘05 V8 SR5. Replaced MAF after cleaning several times and still getting codes. Took it to Toyota Techs in Fort Mill and she had a cracked manifold.

yeah, the cracked manifold is a common issue on the v8, is yours a v8?. mine is v6.
any tips on how to detect a cracked manifold on a v6 runner?

 

[81runner]

yeah, the cracked manifold is a common issue on the v8, is yours a v8?. mine is v6.
any tips on how to detect a cracked manifold on a v6 runner?

Guessing with either engine, a shop would hook it up to a smoke machine, makes it pretty simple. If you are trying to track it yourself, the easiest thing I can think of is to spray the suspect areas, seams, gaskets, hoses and connections, with brake cleaner while the engine runs. If you are leaking vacuum from any of these areas, the brake cleaner will get sucked into the engine and briefly rev up the engine. Don't know of many v6 manifolds failing

 

[earthrealm]

I got both of these codes and the freeze frame for the data shows my long term fuel trims being above 25% (05 Limited 4WD V8). I cleaned the MAF sensor, nothing. Numbers go down as I accelerate

Im leaning towards a vacuum leak, but have no idea where to look for them besides the PCV valve, which just so happens that hose coming from it is pretty "busted up" and kinda cracked. Any ideas?

also seems to be effecting the good ole MPG's quite a bit

had similar issue
replaced all the injectors, problem went away.
you should try that

 

[Trent]

With the right fittings, fuel pressure was easy to test on my 04 V6. If you do test the pressure, be careful as a pressurized fuel leak can be dangerous.