I'm a first-time poster here. I'm a little bit of a n00b, but I have some mechanical skills, and can do most basic maintainence.

This is on a 2000 Civic EX d16y8:
It's throwing a code 90 - showing 9 flashes that seem long, and no other flashes. Could be a code 9, but I'm pretty sure it's a 90.

Usually a code 90 means gas cap, but I'm absolutely certain that I put the cap on tight every time. I replaced the gas cap, just to be sure. Shop manual says that a 90 could indicate EVAP problems or fuel tank pressure. I have no experience working on the vacuum system, but I replaced all the hose from the purge to the MAP sensor, since it was looking worn.

I've also recently replaced pre-cat O2 sensor (it was throwing that code too, originally), plugs, wires, drive belts, and water pump. The belts/pump were due, and I did plugs because they were fouled from (probably) the bad O2 sensor. The code was happening before all of this, and nothing so far has fixed it.

No other symptoms really - car seems to be running fine. Any ideas would be appreciated.

 

somebody? anybody? Bueller?

 

90 Evaporative Emission Control System leak detected in the fuel tank area

most likely the fuel cap went bad. It could also be that your fuel tank pressure sensor went bad or you have a leak in the tank/filler tube.

BTW, https://honda-tech.com/zerothread?id=1171263 has a great video so you can be sure your reading the code right. It also has the codes so you can know what's up right away.

 

90 can be either

- evap system leak in the gas tank area

or

- evap system leak in the charcaol canister area

You have to get it scanned by an OBD2 scanner. Than that will tell you if its the gas tank area or charcaol cansiter

P1456 is a evap sytem leak in the gas tank area

P1457 is a evap leak in the charcaol cansiter area

 

I think I just found the problem. Isn't there normally a little metal piece covering the top opening of the tank filler neck (where you put in the nozzle)? There's one on my Accord (and every other car I've ever owned), but it's missing on my Civic. I can't remember if there was one there to begin with. Can someone look at their Civic and see if there's supposed to be one there?

Thanks much for the help.

 

Never noticed a metal flapper door on my 99 Civic hatch.

Is this a stock 00 Ex?

 

yeah, stock 00 EX.

 

I have a 97 EX has the little flap of metal, all cars do, keeps air from entering the system.

 

that flap is to prevent spillage due to splashing.
the hole in it was/is actually there to prevent you from using leaded fuel (larger pump nozzel size at stations)
in no way does it seal, there are actually slots on the sides to allow fluid to pass if it needs to.

(I feel old now)

 

Scanned the code - It's P1457, I guess charcoal canister area. I've already replaced 2 hoses, I'll try the other two, and then maybe look at getting a new canister or something.

Thanks again for the help.

 

No canisters don't go bad. Check the valve on top of the charcoal canister, put 12v on one pin and ground on the other, and when applied it should click. If it clicks then its good. Then check the purge control solenoid, this valve is between the TB and the charcoal canister, and also put 12v to one pin and ground to the other, it should click open and closed. I have this code on my car and I got it after I did the swap and I bought the helms book and for 2 summers now I have been troubleshooting this ******* piece of **** code. So i know EVERYTHING on the 96-00 civic evap system, I mean everything. I even had it at honda for 3 days, they even said the JDM b16a is fine. and the OBD2 ecu is fine,, but they are stumped, all the hoses have hose clamps and every ******* valve and solenoid has been replaced. And the code is still there. BUT you have the stock motor!!! So now when i was at honda I talked with the head mechanic for 2 hours and the parts girl becasue she has a eg with a b16a in it plus she had some knowledge on doing other swaps. I told them everything I did to test and they told me what they did. So its still there but i passed inspection. But when i talked with the mechanic he said the two way valve and the bypass solenoid ( which are screwed together next to the gas tank next to the driver side rear wheel) are the MOST common problem. But the next thing to do would be to buy a helms manual and buy a vacuum pump to test all the hoses. But I am not about to type EVERY test. PERSONALLY, I know all honda does is plug in a computer and it runs a test and it pin points the bad valve or solenoid right away, so Seriously if you don't wanna spend $80 for the helms book + $30 for a vacuum pump, just go to honda pay the $75 and they will tell you what it is and then you can buy the part and save on installation labor. The valves range from $80-$110 depends on where you buy it so if its any bad valve or solenoid it will be within that price range. So That code is NOT the gas cap, trust me. Everyone and there mom says its the gas cap. So if your a DIY'er then buy the book and start from step One. But if not, this is worth takeing to honda becasue the code can ba a number of things, its not like vtec code or knock sensor code, etc. This code can mean bad hose, bad hose connection, possibilty of 1 of 4 valves being bad, or a corrded wire. Its nuts and takes ALOT of time to test. Ive been through it all, like 100 times. If you lived by me I would be able to find the problem within an hour, with all the testing and ****. But again charcoal canisters only contain charcoal sand stuff and theres no way it can go bad unless you break it with a hammer. Plus the guy at honda said the "last time he saw one go bad was when he saw a melted one after a civic got burned to the ground"