What would cause a code that shows lean on bank 1 and 2?

 

any number of things...

a Vacuum leak

a faulty MAF sensor

low fuel pressure

a bad tune or chip issue

and more...

 

The code came from the Auto Zone hand held code reader. If it was the MAF, wouldn't that itself throw the code? I thought about running injector cleaner through it, and then re-setting the code. Any other thoughts? The engine runs smooth with no signs of any type of problem... other than a service engine soon light.

 

a Vacuum leak

 

having jerry tune your truck

 

you can definately have a faulty maf sensor without setting a maf code.

have you done any other work to the truck or had any tuning done recently?

I'd check for vacuum leaks first, just open the hood and listen. check the obvious hoses to make sure everything is plugged up tight. make sure that the pcv valve hasn't popped out, make sure everything around your air intake boot is tight and in place.

aside from doing the proper testing, you could always borrow somebody elses maf to see if it corrects the problem.

good luck.

later,
chris

 

check and make sure all 3 hoses are connected to the bottom of the intake boot

 

I just posted a thread about a lean code on bank 1, then I saw this post. I just got my truck dyno tuned less than a week ago by Sal at PSP. It ran fine and still runs fine. I got the service engine light while I was putting around a parking lot. No WOT at all the day it happened. The light hasn't come back on since the chip has been out which hasn't been very many miles. I will try it with the chip in and see if it throws another code. If it is due to a bad MAF will it throw it whether the chip is in or not? I replaced the fuel filter a couple of weeks ago and my fuel pressure is in the low 50's according to the gauge. Any other ideas? Thanks in advance.