Please Help CEL P0171 wont go away

Somebody please help me. I am at my whits end dealing with this P0171 CEL light code. I need to pass emissions and it wont pass with the check engine light on.
My truck is an 02 5VZ-FE motor 4WD equipped with the black gen 2 TRD Supercharger

I have already done so many things to try to get this code to go away with no luck. First thing I tried was cleaning the MAF sensor. No change. Then I changed the MAF with a known good Toyota one from another truck. No change.
I have been putting a bottle of fuel injector cleaner in the gas tank every week hoping to clean out the injectors if they may be clogged up a little bit. No change
The O2 sensor voltages are switching as they should from high to low so I don't suspect them.

I searched high and low for a vacuum leak everywhere and found none. I sprayed some intake cleaner all around the intake manifolds- and I swore I could hear the idle slightly changing as I sprayed it, So I thought the intake manifold gaskets were suspect.

I took off the supercharger and lower intake manifold and replaced upper and lower manifold gaskets along with the throttle body gasket. Along with a good throttle body cleaning.
After putting it back together and starting it, a couple of fuel injectors were leaking gas, so I had to take the supercharger back off. This time I replaced the injector O-rings and the injector seals that seal against the manifold.
I've changed the fuel filter, air filter, spark plugs, PCV valve and PCV valve hose. I've done an on car throttle body intake cleaner service, ran it with sea foam.....I don't know what else to do, this is why I am now asking for help.

I have heard that a lot of trucks with superchargers have issues with this code. I have also hear about people installing a 7th injector kit, that helps this issue. TRD claims that this 7th injector kit or a bigger fuel pump are unnecessary. And I am not on a budget where I can afford to buy the $875 kit right now.

My question is...... IS THERE ANYONE OUT THERE running the second gen black supercharger on the 5VZ-FE motor WITHOUT the 7th injector kit, that doesn't have the CEL on with code P0171? Any help would be greatly appreciated.

 

did you reset the code after you did the changes? if not, it will still be in the ECU. Try to diagnose some more, throwing parts at a problem is the expensive way to go.

 

Yes, I cleared the code after every time I made a fix or repair, and every time the code popped back after 2 trip cycles.

JudoJohn, will you please tell me some steps to take to diagnose, what are you talking about? I am addressing all the areas that would make this code pop up and make the engine go lean. There are no diagnostic steps to take to figure out if your injectors are clogged, there is no diagnostic steps to take to find that the fuel filter may be partly clogged or my fuel pump may be weak, besides fuel pressure. (which was within specs) There is no diagnostic steps to take to check the MAF sensor (the voltage is within range when watching on a scan tool), there is no diagnostic steps to take to find a leaking intake gasket or leaking injector seal. There are no diagnostic steps to tell you your spark plugs are getting weak. I'm not just trying to throw parts at it, but....its kind of just trial and error at this point.

The truck drives absolutely perfect! Nice smooth idle, no roughness, no misfires, no loss of power, just has the stupid light on the dash.

 

I see that you said the MAF voltage range is within spec, but maybe you should try cleaning it. Paper towel and MAF cleaner spray. It did it for me, and we went through EVERYTHING on my truck before we tried it.

 

^^Fenwick, if you read my original post, I mentioned that the FIRST thing I tried was cleaning the MAF. After that didn't work I swapped my MAF sensor with one from my buddies truck with the same 5VZ-FE motor and same part number, that was a known good one with no issues or codes. Cleared the code and it came right back again after 2 trip cycles. That is why I kind of ruled out the MAF sensor as being my problem.

 

Oops! Skipped over that unintentionally. My apologies!

 

Did you smoke test the engine? It's possible to do with a dollar cigar with the engine off, just blow smoke in a vacuum line and check to see if it comes out anywhere. Are there any exhaust leaks?

 

^^No I never smoked tested the engine. I thought about it, because I know someone with a smoke machine, but when I asked him he said it was broken. I never thought about doing it with a cigar. And no I don't have any exhaust leaks and everything cat back is new.

 

what is the short and long term fuel trim readings?

 

^^ I just went out and checked. My short term fuel trim at idle keeps changing from about 3.4%-10.2%. More frequently staying in the 6.8-9.4% range. My long term fuel trim is up at 35.9% This data was collected with the CEL light On.

Now I am very confused....... I just went out to double check and test it again, and this time the CEL light was Off and all the monitors were reset like I cleared the code or something, but I didn't? Now the Short term fuel trim is reading at 19.5-20.3% consistently. There is no data for the Long term fuel trim now. And I noticed that my B1S2 O2 sensor is now Very lazy! Staying at 0.0V for a long time and even when gassing it, only going up to .3V This is very confusing because it was just operating and switching perfectly when I did the first test.

*edit*
I don't know what that was about....anyways but I was monitoring the data on my way to and from work today and now the O2 sensor data seems more within spec switching from .1V to .7V. The Long term average fuel trim is about 19.5% and the short term while driving ranged from about (negative) -3.4%to +6.4%. saw it go up to 16% once as I was slowing down to a stop.

The check engine light never came on yet either. 35 mile drive to work both ways and no CEL yet. I'm sure its pending, but I never checked

 

Forgive me if you said somewhere, but what type of filter are you using? And have you done any mods to the intake box? I cut my air intake elbow off just through the fender to help with air flow and also did the deck plate mod in the front of it. I have messed around with dry and oil filters. I can't get my 0420 code to stop poppin, but I only get the 0171 when I run a dry filter. What size tires you running? Do you have a air/fuel gauge? I never had any codes until I started running my bigger tires. The comps on these things are kind of retarted without being able to plug n play :/

 

Check your throttle body gasket and iac valve gasket. Also clean your iac valve while you're at it. This is what fixed mine. Also If the TB gasket is not oriented correctly, it will leak and throw a code.