01 blazer service light came on

[blazer_01]

I am new to this forum I have a problem with my 01 blazer it is 6cyl.
the service light came on the other day. I checked all the fluid levels and they are ok. It does not run rough not sure what it could be. Not sure if it could be a vacume leak but all the hoses I see are still in very good shape
one other thing it started ok with no light when I went to work but when I got out of work the light stayed on??
Help if you can

[curtis73]

Its probably an emissions issue. Stop by your local chain auto parts store and they'll have a code reader. It should be free... don't pay for it. If that store doesn't do it free, go to the next one.

Post the codes when you find out what they are.

[blazer_01]

I just went down to the auto parts store and had the code read
it was a PO440 which is evaporative emmission control systems
I also replaced the gas cap

[curtis73]

Probably the evap purge solenoid. Check the fuses, have the solenoid tested, replace the gas cap (good job), and try resetting the code by leaving the battery disconnected for several minutes.

It could be a one-time oops. Do you always top off your fuel tank? If you do the evap system can suck raw fuel into the charcoal canister and ruin it. You shouldn't top off tanks; just go until it clicks once.

[blazer_01]

Could you tell me if the fuses are under the dash or the engine
also where is the solenoid located?
I do not top off when I fill up I have about 3/4 of a tank it has been about a week or so since I filled up
thank for all the info so far

[UncleBob]

you probably had the gas cap loose. Thats the most common reason that code happens. Hopefully the new gas cap you put on matches correctly, some of the aftermarket caps are....questionable

I wouldn't make any guesses beyond that, other than to suggest, if it comes back on, most likely its a leak, and randomly replacing stuff would be expensive. Just get the system pressure tested, its usually fairly obvious where the problem lies

[blazer_01]

I see the fuse box is in the engine those little bugger are hard to get out will try looking at them tomorrow
the gas cap was not loose
tried both new & old same situation I think it maybe something else I may look into trying to see if I can find out where the solenoid is at

[UncleBob]

there is no fuse that is directly related to the EVAP system.

If you are sure the gas cap wasn't loose, time to take it to a shop and have it pressure tested. The solenoid would cost more than the diagnostics, and I'd bet you $100 it won't fix it. Don't know how much you're into gambling, but i could use the money if you don't need it....