2007 TRD P0171 lean code

I've looked all over & cannot find the info I need to properly trouble shoot my issue. I'm getting 171 trouble code (lean system). Issue only occurs after engine is up to temp. Then whenever throttle is applied the engine stubbles & shuts off.
According to my scanner my MAF sensor is at .5, short-term trim is about %0 and long-term trim is about %28. All at idle. I can't find what those numbers should be anywhere. I know the MAF # seems low & long-term trim seems ridiculous high. I've looked for vacuum leaks & cleaned the MAF so far & no luck.

Any help would be awesome
2007 TRD V6 double cab

 

Any1?

 

About 2 yrs. ago I got the opposite code P0172 in an '06 Toyota Avalon. P0171 - lean & P0172 - rich. When you look these codes up you learn it can be all kinds of things.

I had only a code reader then and took a shot at cleaning the MAF sensor with the CRC Mass Air Flow Sensor product. After cleaning and clearing code, I never saw the P0172 again. Not saying this will solve your problem, but the MAF does need to be cleaned once in awhile.

Here's the Tacoma FSM - you can likely find the Percentages in it:

http://www.customtacos.com/tech.old/files/05FSM/repair.html

 

Thanks Lester, yeah I already cleaned my MAF sensor. Didn't do squat tho. I'll try to decipher the FSM - lots of info.
Thx again

 

No one really?

 

I'd look at vacuum hoses for cracks and whatnot. Throwing a lean code tells me there's unmetered air getting into the system. A can of carb cleaner with the engine running will help pinpoint any vacuum leaks.

 

If the trim is close to zero at cruise and only goes hi at idle I would definitely look hard for a vacuum leak

 

I changed out the MAF sensor & that's not it ( code hasn't came back yet but still simular OBD readings). I disconnected the fuel line near tank & let a gallon pump into container & all looked good. I tried the carb cleaner but it doesn't change rpm even when sprayed into intake. I do hear a sucking noise near rear of engine ( at firewall) when I punch throttle, but not able to pin point yet.

 

Any1?

 

As far as trim goes short struggles to stay around 0, long term trim goes from around 15% up to the high 30's under load.

 

Really?

 

Try posting in the Technical Chat forum. Hopefully you'll get some more feedback there.

 

You ever find the source of that sucking sound you mentioned?

 

No, im beginning to think its just the intake. Im just hearing it more with the hood up & The motor almost shuts off when I pat the gas. I'm really at a frigging loss here.

 

How does it idle? I changed plugs one time and forgot to reconnect the pcv valve hose. Idled like sheet and would almost stall when giving it some gas.

 

It idles ok, a tiny rough at times. It will take throttle when it's cold, but when up to temp it stalls when given throttle.

 

Got a buddy who can play with the throttle while you poke around under the hood?
I'm still leaning towards some kind of vacuum leak. It running "ok" when cold kinda sounds normal because the engine is running rich when it's cold.
Take that can of carb cleaner and spray the entire length of every vacuum hose and fitting you see. RPM should go up when the leak is sealed with the liquid.

 

I've sprayed at every place I can get to and found nothing. I was looking at obdll data & I noticed the "CATEMP's" way different & I have no idea what this means. Catemp 11& 21 are about 800°f while catemp 21& 12 are about 400°f. Trying to find out if that means anything to me.
***edit - looks like those #s are probably ok.

 

Does your tool show a calculated load % reading? When you go full throttle to go up a hill that reading should go over 75-80%. What are the grams per sec readings at the maf sensor? Throttle position and maf are used to calculate load %.

Do the fuel trims go hi at idle or under acceleration?

 

Spray soapy water or carb cleaner on your hoses and connections to test for leaks, this code is usually due to a vacuum leak.

If not, and you're sure the MAF sensor is okay, then I'd look into replacing the O2 sensor