I have a lean code comming up and dont know what it is

I have a 2002 tocoma reg cab and my engine light came on and I took it to Auto Zone and they said it was a lean code that came up ( I dont know what the code number was, but it was a lean code ). So, I repaced the MAF and that didnt help. Im thinking it could be the a/f sensor but not reall sure,or it could be a vaccuum leak. How can I be sure what it is insted of spending $65 to hooked it up to a computer? Or would that that be the best thing to do is hook it to a computer? Im pretty low on funds and trying to get out of this cheaply

 

Too much air, not enough fuel. Look into all your fuel delivery components.

 

Yes..I understand that is what that code means.. and I did..and I still dont know why im getting that code

 

Other than the MAF what else have you done?

 

I mean the first step is to know what code it is. Advance still does it for free. They don't clear the codes but they will pull them. Might be an oxygen sensor unless you've replaced them recently (There is a faulty O2 sensor code but they could also be bad and messing with your mix). After that you could need a fuel filter, new injector(s) maybe.

You need to know which code it is unless you've got money to blindly throw at the problem.

 

Best thing is get an actual code number. That rules out a lot of possibilities.

 

Did you? I'd start at the tank, and go forward. Mainly, pump, filter, injectors.
But first, find out what the code actually is.

 

Orieily's or autozone will read the code for you. Use that to look up the possible causes. The store may give you the top 5 likely causes when they print it out.

 

You can also get your own code reader for like $40-50 on ebay or whatever. If you have to pay for it, may as well.

http://www.ebay.com/itm/ODB-II-2-AU..._Automotive_Tools&hash=item2ec448d14b&vxp=mtr

I think that's the exact one they use at Advance Auto.

 

There are two different lean codes, P0171 and P0174. '1 means the problem is on the side of the engine with the #1 cylinder. '4 is the other side.

When you step on the gas, does the vehicle seem hesitant or does it go like it has before? At idle, is the engine smooth or does it run rough?

If either of these is happening, more than likely the problem is not related to the MAF. Instead, look to the vacuum system (leaks), PCV and possibly a fuel injector. Could also be a dirty fuel filter.

Also, before you try anything more; did you clear the codes after you replaced the MAF? If not, try doing that first (assuming the engine is running smoothly).

 

repalced the #1 coil pack..plugs..and the egr valve..i forgot the exact code for it..but it was a lean code

 

If you do this, why not upgrade to an ultra guage? That way you have more functions.

 

it was a po171 code..i did clear the code when i replaced the MAF and the truck runs real good..smooth..im think a leak somewhere

 

and its a 4 cyclender..the 2.7

 

its generally either 02 sensors, shitty injectors "doubtful" because youd probably have a miss fire... or an exhuast leak could be causing it also

 

had both exhuast gaskets replaced like a year ago..im thinking the a/f sensor..thats $230 at a dealer..and toyota is VERY picky on any electical parts to put in

 

Question, if you clear the codes; when does the CEL come back on? Is it at engine start or after you put the truck in gear and drive away?

If it's the later and you haven't swapped the fuel filter, I'd change that.

 

it comes on like 16 miles after i cleared the code..it runs smooth abd all and i think the fuel filter is in the gas tank..no sure

 

I think I remember seeing somebody with a first gen say it was located on the frame rail. May be off on that. I think in the 2nd gen it is in the tank.

 

how would i know what gen it is..im thinking mine is 2nd gen cause i havent seen a filter