My check light comes on randomly while im driving and stays off a while once I clear it. I pulled the code and it came up code 90 which is p1457 referring to the evaporative emission system. Does anyone know what could have caused this or has it happened to anyone else? Also, I always keep my fuel cap tightened well and use premium fuel so that could not have caused this.....

 

Things to check:
1)Fuel Fill Cap
2)Vaccum connection
3)Fuel Tank
4)Fuel Tank pressure sensor
5)EVAP bypass solenoid valve
6)EVAP two way valve
7)EVAP control canister ventshut valve
8)EVAP control canister
9)EVAP purge control solenoid valve

 

Do you have a gas cap? Or maybe you just need to reset your ECU. Take off you ground wire on your batter for awhile, then connect it and see if it comes back on...

 

nah, I reset the ecu and it stays off for a while then the light comes back on randomly..... also , when i open my gas cap even when ive been driving i dont hear any pressure sound.... is this normal or do you guys hear a pressure sound when you open yours?

 

I don't always hear that presure sound, but sometimes I do. You might wanna take it in and have the dealership look at it. Something like this should possibly be covered under warranty if you still have it

 

well also.... i need to find out from someone who has a 99 prelude also what connects under the middle of the cold air intake.... cause when i bought the car it came with an AEM cold air intake and one sensor or something that hooks into the vacuum box underneath the intake is disconnected and no box is there...... this could also be the cause of the check light

 

That is the activation swith for the vacuum system that runs the butterfly valve in the stock air box. Since the airbox is no longer there, it is no longer needed. You also need to make sure the vacuum line in plugged which went to the stock airbox. You can stick something like a golf tee in the end, or trace it back to the TB, remove the entire vacuum line, and cap the nipple at the throttle body.

 

ok, I did that, but it looks like a sensor used to be plugged into that little vacuum box, does this need to be plugged in to somewhere or how did you do it? also..... does your check light ever come on due to this?

 

Just leave it unplugged... You might want to tape it up to keep it from shorting out and blowing a fuse... I've never seen a CEL from it, and looking on my code list, I don't see one for it so you should be okay

 

well the light that came on was not due to this I do not believe..... the code that came up was p1457 which is something in the evaporation system related..... and the fact that I never hear a pressure sound when i open the fuel cap could be another problem... the thing thats weird though is that the code only comes on randomly and stays off for a while once I clear it.... some people suggested it could be the purge or purge valve since that is what builds up the pressure in the gas tank....or that I could have a leak somewhere.... but its not leaking gas whatsoever