i just got a 2001 blazer and it threw a evap code does anyone have any idea what that could be or what could or what could be
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I believe that there is more than one evap code. Knowing which code may help narrow things down. But, in general, here's a list of things than can generate evap codes:

· A disconnected or malfunctioning fuel tank pressure sensor
· A missing, malfunctioning, improperly installed, or loose fuel cap
· A disconnected, damaged, pinched, or blocked EVAP purge line
· A disconnected or damaged EVAP vent hose
· A disconnected, damaged, pinched, or blocked fuel tank vapor line
· A disconnected or malfunctioning EVAP purge solenoid
· A disconnected or malfunctioning EVAP vent solenoid
· An open ignition feed circuit to the EVAP vent or purge solenoid
· A damaged EVAP canister
· A leaking fuel sender assembly O-ring
· A leaking fuel tank or fuel filler neck

My personal experience has been that the most frequent offenders are gas caps, and purge solenoids...both are cheap, quick, easy things to eliminate.

If one of those doesn't help, I'd suggest moving through the list in order of least costly and time consuming items, to most costly and time consuming items.

After fixing the problem, assuming you've found it...it's going to take a while before the SES light goes away...unless you have someone with a scanner erase the code. If I remember, erasing the code also erases the computers evap system test data...which means that your computer will show that the evap system test is incomplete, immediately following erasure. I can't remember if an incomplete system test is enough to hurt an emissions inspection. Anyway...it'd be worth checking out.

Personally, I don't like erasing EVAP codes for those reasons.

Icarus

 

Yeah, if you are going for an inspection and you clear, then you will have to do a complete drive cycle to get all of the systems to the 'ready' state.

Most often, this is related to a faulty gas cap seal or just a loose gas cap. Have you recently filled up with fuel? Did you turn the cap until it clicked atleast 3 times?

The next peice that triggers this is typically the vent solenoid that is located at the back of the vehicle. It's a nice place for things to build nests as well as just normal road debris to collect and plug up the plunger. When I replaced mine, something had eaten through the foam filter and built a nice nest inside. They aren't too terrible expensive, especially if you have an AC Delco retailer close by, but there are plenty of aftermarket equivalents that probably work as well as the AC Delco unit. Sometimes you can just clean and relube your current valve and have it work. In my case, it didn't actuate when bench tested...

Anyway, hope this helps!