he didn't I was just referencing james
My 2004 Tahoe threw a P0442 code
- Thread starter ueww40
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
Sorry @swathdiver I didn’t see that you were chasing this problem also. Thus my confusion. Carry on. Those prices were for the OP’s 05.
I have also been chasing this stupid problem forever it seems like. The problem for me is that I can check the functions of the valves but there’s no way I could see by using the Tech 2 to see if there was a leak at them. Mine was a small leak also whatever that means, and the code pops up so randomly. Sometimes it’s a month or two or three. I had replaced both valves and thought it was fixed but 3 months later it came back. So I just replaced the canister last week, and in the process I found a pinched hard plastic line that must have happened when I dropped the fuel tank to change the fuel pump. I fixed the line by splicing in rubber fuel hose. I won’t know if I fixed it for at least 3 months lmao.
swathdiver
Full Access Member
On the GMT900s the test is run cold with the motor off. ECT has to be below 158 degrees, I found out the hard way trying to help a fellow member and his truck was too hot and those little 500 watt fans on his would kill the battery before bringing the temp down so we resigned to run it another day.
OP
OP
ueww40
Member
- Joined
- Aug 5, 2017
- Posts
- 43
- Reaction score
- 17
I came to the same conclusion. since I didn't see any smoke leaks I will assume for the time being that all the tubing and lines are ok. The 3 suspect parts (purge valve, vent valve, gas cap) all OEM are on order from Rock Auto totaling $55 and should be here by the end of the week. Will then replace them one by one and see which fixes the problem, if it does fix the problem. If not back to the think tank. Will keep you all posted. Thanks for all the great info.
Same here. It’s frustrating bc you change a part code goes away so you think you’re good only to have it come back 2 weeks later. I got lucky in that the hose to my tank was split and came off so I could see the problem but not before a gas cap and purge valve but heck they were 12 yo too.
OP
OP
ueww40
Member
- Joined
- Aug 5, 2017
- Posts
- 43
- Reaction score
- 17
I replaced the gas cap, the purge valve and the vent valve and drove it over 120 miles in 3 days with the hopes that the computer decides that the small leak was fixed and turned off my check engine light, but the check engine light is still on. So I was just about to give up and take it to a shop. Today I went to Advance Auto Parts and ask the guy there to do another reading of my error code to make sure that it is still the same and to my surprise he told me that the computer WILL NOT TURN OFF the check engine light, even if the problem has been fixed. Now that would be horrible. IS THAT TRUE? He said that the only way this check engine light goes away is by resetting it, which he did. Now let's see if the light comes back. This problem may have been fixed weeks ago unbeknownst to me thinking the light goes out when it's fixed.
You have to either clear the codes with a scanner or perform a certain amount of drive cycles without any issues. That number depends on the code. Get yourself a cheap $20 scanner that can read and clear codes. It’s well worth the money. FYI this is nothing new.
HiHoeSilver
Away!
Certain codes will go away and the light will go off on its own, but it may take something like 50 drive cycles to do so. Some will not go away unless cleared by a scanner. I'm not sure which category the evap codes fall into, but I do seem to remember my po449 light going away and then coming back on its own at some point...
