Need Help Fast with EMISSION

[wildlifekid]

Just recently replaced the bypass cut vavle and the other control unit that connects to the bypass cut valve. So that cleared the codes I had. But now I noticed that when I removed the gas cap when filling up there is no gases or pressure coming out. And now I have a code P0440 which is a small leak.. What could be wrong... Need to get back that pressure in the gas tank... Can't pass emissions!!!! Any help PLEASE!!!!

[wildlifekid]

Could it be that the (SENDER UNIT-FUEL GAUGE) be bad? If so how hard is it to changed it and what parts do i need other then the Sender unit itself??

[alexf20c]

so why can't it pass emissions? the whole purpose of the valve cut bypass valve (EVAP purge) is to vent the pressure buildup from the gas tank into the intake manifold. under normal operation, there will be no pressure release when you open the gas cap.

do you have a CEL? what exactly is making it fail emissions now?

[wildlifekid]

After 7 to 10 days i keep getting the Engine light with code P0440 which is not making me pass the emission test. I just happen to noticed that before when i use to fill up the gas tank and i would remove the gas cap there would be some air coming out (like if there is pressure). Now i don't get that air coming out. I already replaced the gas cap and the other two sensors. I have took it to the emission test already 2 times it had failed saying that evap is not ready and the 02 sensor is not ready.

[Chuck Tribolet]

If there's an O2 sensor problem there's another code than P0440.

To fix the P0440, you gotta find the leak.

[alexf20c]

After 7 to 10 days i keep getting the Engine light with code P0440 which is not making me pass the emission test. I just happen to noticed that before when i use to fill up the gas tank and i would remove the gas cap there would be some air coming out (like if there is pressure). Now i don't get that air coming out. I already replaced the gas cap and the other two sensors. I have took it to the emission test already 2 times it had failed saying that evap is not ready and the 02 sensor is not ready.

ok so do you have a CEL or not, when you take it to the inspector? a Not Ready status is completely different from a Failed status. Not Ready means the circuit has not had enough time to recheck itself to clear the code. Failed means it has run the test, and you did indeed fail.

every time you disconnect the battery or clear a DTC, it sets that circuit's status to Not Ready. if you DO NOT have a CEL, but are still failing the test, you need to drive the vehicle at cruise from 50-60mph for a few miles, once the engine is already in Closed Loop (warmed up). that is when the computer will check those circuits. you need to be cruising at 50-60mph.

if you DO have a CEL, then it's something else that needs to be replaced. are you blindly throwing parts at the car, or are you actually diagnosing it or having someone else diagnose it?

the "air coming out of the gas cap" diagnosis is not exactly accurate. in fact, it indicates absolutely nothing relevant to your problem.

[wildlifekid]

The reason i replaced the bypass valve in the first place is because I got the code for that part. When I replaced that part the other sensor that is hooked up to it had one of the plastic tube crack off. So i just replaced that sensor aswell.. I do get CEL after about 7 to 10 days of normal driving.. That's like driving maybe about 5 to 10 miles if that of city driving. I will driving for a period of time while going 50 to 60 miles per hour and see what happens then. I have checked the hoses and the charcoal canister for any leaks or cracks. I have yet seen anything yet. I just don't want to take it to the mechanic and have them charge me an arm an leg for something simple that i could of done. Any thoughts????

[alexf20c]

P0440 is the exact code you're getting NOW, or that is the code you got earlier?

you need to have the code rechecked.

[wildlifekid]

That's the code that has been coming up.. this weekend I'm going to check the Bypass vavle hoses and make sure the clamps are on it tight.. Maybe that's where I'm getting the leak from... Any other spot I need to check ???

Thanks for all the replies...