im in need of some help here. i was experiencing a hard start issue a few weeks back. i determined the problem to be a failing fuel pump so i put a new pump in also had to replace the tank and what a headache that was. after i had her all back together she ran good and my issue was resolved. after i started driving her again i started getting a SES light code p0442 i cleared the code and for a couple weeks no code then cruising along going about 45 light came back on and again p0442. i just kept clearing the code since the engine runs smooth and drives great and im still getting 14.5 mpg. code seems to stay off for a couple weeks then comes back. today when it came back i got a p0440 i know its the EVAP system but could someone point me in a certain direction. i replaced the tank cause i broke that damn nipple on the tank vent dropping the tank

 

Both DTC's are indicating a problem in the EVAP system. The P0442 indicates a small leak, (classified as .030" or smaller). Following the steps in the flow chart will take you to the problem: https://blazerforum.com/forum/diagno...plained-35144/

Here is the one for P0440: https://blazerforum.com/forum/diagno...plained-35145/


You need to diagnose & repair the DTC's in the order they are retrieved.

The reason the SES light takes so long to come on after you clear it, is because the steps necessary to run and complete the test have not been duplicated. The EVAP monitor can take days, weeks, even months to run. If the drive "pattern" is not duplicated, it will not complete. You can force all monitors to run, and complete their tests by performing the General Motors Driving Cycle

 

I had the p0440 code, just replaced the solenoid assembly from one I got at Pick n Pull. Haven't had the SES light since...


Good luck!

 

the one mounted on the intake?

 

No, the one you gotta remove the spare tire to get to..

 

Have you noticed a strong gas smell at all? I had to change the one under the spare tire because it went bad. I could smell gas pretty strong because it was stuck open.

 

Didn't have any smell, but the SES light was on and the DTC code was that..

 

never smell gas just have the annoying light and have to clear it every couple weeks. today i filled the tank 3/4 full and have not seen the light yet ill keep you all posted when it does.

where is the one under the spare tire? does anyone have a picture of it?

 

Just drop the spare tire and you'll see it..
it's mounted on a bracket with a 10mm bolt.


The hardest thing about it to me was trying to figure out how disconnect that weird *** clip holding that line to the solenoid.

 

the winch holding spare in has long since rusted and froze so before i got the vehicle somebody cut the wire and removed the spare. when i replaced the fuel pump i didnt noticed anything. ill take another look when im replacing my ball joints this weekend