Check Engine Light!

Hey everyone i need your help. I have a 99 limited with a 3.4. since about a month after i bought my rig the check engine light has been on(about 9 months now) i bought it from a dealership and love my rig. I have now replaced the fuel filter, air filter, pcv valve, had the oil changed twice and even up graded my oil(for different reasons) a mechanic at a local toyota dealership told me that it was most likely the fuel filter, which did not fix the problem. i figured the cat was maybe plugged and needs a new one or straight piped(no emissions laws where i live) if you have any idea what the problem could be let me know. thanks!

seriously man, we need MORE INFO. 
 
FIRST--What are the codes for it
 
SECOND- Is the truck running bad?

Hey thanks for the reply the thing is is that i am do not know where to check for the codes. As far as how the truck runs it seems to run pretty good it feels a little sluggish with throttle response but i am not sure if that is how they all are

Probably something small, take it to just about any local shop to read the codes or the dealership you bought it from....  Most local places will do it for free..

Alright thanks for the help i'll see what happens.

Good luck and let us know, it could be something chessy..

Yeah i sure hope so cause i don't want to spend to much money. I am headed to the local mechanic in a little bit and i will keep you posted.

So it turned out that my check light was for a code 171 which is left bank lean. The mechanic cleaned of the carbon build up on my mass air flow sensor and turned off the light and it has yet to turn back on thanks for the help.

Cool deal...  Glad to hear it.