Crimsonnaire

iTrader: (1)

Would anyone happen to know what part might cause the service engine light to go on with the codes, P-0440 (Evap Emission) and P-0442 (Evap Small Leak) in a '99 TA?

It was suggested to me that a bad gas cap could cause these codes, but aside from the cap, what else could cause them to go on? The light disappears for a while every now and then.

I was told that it could cost $500-800 just to have this professionally taken care of!

2001NBMZ28

Yeah check/replace the gas cap first. Buddy of mine had just the EVAP small leak code and a local shop found it by pressurizing the system with smoke. Put a little epoxy over a leak and it fixed it. You can also visit gearchatter.com and look up the codes for other possibilities.

Crimsonnaire

iTrader: (1)

Thank you very much for the web link. I'm still going over the details on the diagnostic criteria. But the more look, the more I'm convinced that I won't be able to fix it myself.

Is there a shop I can take it to that costs less than Meineke to do this? How much did that shop charge your friend?

joshp14

iTrader: (5)

Gas cap is most probable cause, other wise a faulty vent valve or a leak in an EVAP hose or fuel tank will cause this code to set.

keliente

iTrader: (22)

I don't see why it would be so expensive to fix.

SOP for evap system is to check it over visually (looking for cracked hoses) and if nothing is obvious, use the smoke machine. I have never charged anyone more than an hour's diag time ($80-$100) to find a leak.

MOST of the time when you do find the leak, it's a rubber hose that can be replaced that doesn't cost too much...

I think if I couldn't fix it myself I might *gulp* go to the dealer...at least they'll be more familiar with your EVAP system and won't be chasing their tails on it like a meineke might.

Crimsonnaire

iTrader: (1)

I had already replaced the gas cap a while ago, but the light persists. Could a gas leak from another vehicle parked closely set off these codes...?

Meineke charges $100 for the initial electronic diagnostic, plus the cost of the part and labor will add up good. The guy told me straightforwardly that the cheapest he's charged for this kind of thing was around $500. I want to get rid of because if something else goes wrong, the codes will get mixed with the present ones, and I won't know anything because the light would already be on.

joshp14

iTrader: (5)

No a leak from another car wont set off the code in your car. It measures the amount of pressure lost in your EVAP system using the fuel tank pressure sensor and some algorithms programmed in the PCM. It can detect a leak as small as .020" (might be .040" but cant remember for sure). The EVAP system is tough to find a leak without actually hooking up a smoke machine to visually find the leak. I would get under the car and do a good visual inspection of all the evap lines and connections. Check the connections at the purge solenoid at the intake manifold and make sure the connections are both snapped into place. Check for points where the hose could be rubbing on something causing a small leak in the line. I have replaced more faulty vent valves for evap leaks then anything. But from all of the actual lines that leak, I have had more hard plastic line leaks on the EVAP system then rubber line leaks as there are hardly any rubber EVAP lines on GM vehicle anymore.....and I do work at a dealer.

Crimsonnaire

iTrader: (1)

Would you happen to be referring to the tube that the red arrow is point to?


The twist cap in front of the arrow is missing on mine. I've always wondered what that's for, or if it's supposed to be covered.

joshp14

iTrader: (5)

Thats the fuel rail schrader valve cap....that just keeps dust out of that port that is used to check fuel pressure. Directly below your arrow is the EVAP purge valve...it has a tube coming out each end and a red connector going to it. The tube that comes out the front makes a right turn and goes into the side of the intake manifold. The base of your arrow starts on one of the EVAP lines. The other lines runs next to the fuel line through the foil wrap.

Crimsonnaire

iTrader: (1)

OK, I see it! I'll check this first thing tomorrow. Hopefully, it's not a serious problem, since the lights went away for quite some time.

Thanks for the tip, Josh.

2002 SS #476

iTrader: (2)

A P0440 code is almost always, always, the gas cap (especially if the light came on after you filled it up). Make sure you have it tight. It may not go off right away if the cap was loose and you tightened it. The system has to run its test for leaks (pressure) before the light goes off. Sometimes its awhile before the test runs with that system.

If you know someone with a scan tool, have them clear the code after you make sure the cap is tight. Then see if it comes back on before you pay some "professional" to diagnose/guess what the problem is.

Crimsonnaire

iTrader: (1)

I specifically remembered the light turning on when I started to accelerate with the RPM's going up. So I got the impression that it has something to do with whatever is associated with acceleration, which unfortunately could be many things.

This was many days since I filled gas, plus I already replaced the gas cap with a brand new one a while ago. Incidently, I noticed that the plastic ring that sits around the gas tank hole (below where cap sits on) was twisted up with the wire pulled up a bit. I turned it back and let the excess wire length go down into the little wire hole. It was after this that the light went away for about a good week.

Could a ruptured intake manifold set off these codes...?