The first day it was ok but the next day, the check engine light came up, why??!?!

check all your connections and make sure they're in the right place...

if they are, go get a code pulled and post it and then someone will tell you what you need to do.

reset the ECU. worked for me.

what cai

ebay
aem (gen 1 - 2)
injen (gen 1 - 2)

?
if you continue to get cel's your maf is most likely incorrectly positioned and you need a new cai.

- reset ecu
- let engine run for 20 minutes (don't press accelerator during this time)

can also search celica threads for more info. Makre sure all leada are plugged right that were not used. Can use large screws to plug it up then electrical tape to sela it off. Make sure it int here good but that it wont suck up the screw

i had the same problem dude,came up a few times,reset ECU a few times didnt work, avoid gettin water into ur MAFS and clean it. After i cleaned it wit throttle body cleaner wit a q tip and it was gone.

Don't need to do the latter part. Just disconnect the negative terminal of the battery for a few mintues and there you go.


Oh yeah, i have an ebay INTAKE, AEM replica Gen1. No bogging or CEL. had a cel after two days after install, but went away after a RESET.

I have a cel for a different reason...blown cat

sometimes it comes from your computer reading that the air/fuel mixture is too lean, this is why mine comes on...i do the reset thing and if i keep it in the right mixture(actually use my air/fuel ratio gauge) it stays off, but the instant i start to give it hell the CEL comes back on... just my two cents