After replacing EVAP stuff Tahoe is not running right

[BrownSunshine]

So my wife’s Tahoe had a P0440 code. Dealership did a smoke test and said the EVAP Canister, purge valve and vent valve needed replaced.

Instead of paying them 1000 to do it, I replaced them all myself. Reset the check engine light and all was fine. Or so I thought

Now, her car acts like it wants to die and idles VERY low 200-300. But it only does it sometimes. We don’t drive her Tahoe that much (usually take me truck) so since the parts have been replaced we’ve only put maybe 20 miles on it. It seems like it is getting better but then saturday night we were coming home and when I pulled into the garage it was idling at 300 rpm and acted like it was going to die.

I’m stumped. No check engine light.

Suggestions?

 

[swathdiver]

Seems like something else is amiss.

 

[Forrest0125]

Not gonna lie evap issues are a crap problem to have. Just time consuming finding the culprit. Monitor systems on the evap would throw a code tho, im with diver there sounds to be something else amiss. I would assume this would throw a code but theres a control module that regulates current to your valves based on psi or fuel level? Not 100% on which but level and psi kinda go hand in jand, but anyways thats the cheapest thing i can think of that might cause the issue to be intermittent? Maybe the purge vacuum? If a leak in the vacuum youd notice at idle for sure but maybe not initially until it runs and gets backed up.

Like i said time consuming crap problem. Keep us updated tho i see this in my future one day also......again

 

[about20ninj45]

Did you blow out the lines for the evap? Sometimes the lines become clogged and cause issues.