Ok...ive been searching for a while and these seem to be related to the Evap solenoid above the rear end. I changed that and still getting these codes. Everything looks in good shape. What else could throw both these codes? Any help would be great!!

2002 GMC Jimmy 2 dr 4X4 SLS

 

I'd say google them but make sure you put it like GM P0449 otherwise you'll get lots of hits for Hyundi's, Toyota's etc etc, maybe try a GM site & search for codes?!
also try it as an O & a 0

 

Ive been doing that and it all seems to lead to that sensor that ive replaced. Donno what next to do.

 

A friend of mine often says "just because it's new doesn't mean it's good".
Might be a faulty sensor. Still got the reciept?

 

P0449 is a code which gets displayed when the PCM checks the fuel tank vent solenoid circuit for electrical integrity. The value read by the PCM should be between 8V and 16V (basically battery voltage). The vent solenoid is not the same as the purge solenoid so it really depends on which one of these valves you replaced.

P0453 Explained

 

I replaced the one over the rear axle. Where is the other one? 3 sensors now...im not buyingg another. I Also cleaned all the electrical connections, and the filter. The light has been on for a few months now, and now that summers comming I want it fixed. I plowed all winter with the light on, but ill be hauling my derby car all summer. And I dont want anything afecting my fuel milage.

 

The one above the rear axle is the vent solenoid. I would inspect the wiring to the vent valve starting by checking for proper voltage and ground at the valve itself. Then test each wire continuity to ground.

 

Ill get a voltage meter tuesday and check it. Family day is tomorrow, so everything is closed. Thanks for the help!

 

I finally figured it out... 2 of the 4 secondary O2 sensor wires were cut. I re-joined them and SES light is no more!!! I dont understand why I got those lights and not a secondary O2 light. Weird...

 

Glad you got it fixed!