P0171, but only when it's over 70 outside?

[granpajo]

Hello,

Kids sonic is throwing p0171 code. It threw that code last summer but stopped throwing the code and to be honest we forgot about it. It was absent the entire winter, but now that it's warm again we're seeing the code again. I'm thinking it's a vacuum hose issue that's opening up when it's warm, with the MAF. So basically just asking if anyone else concurs? The O'Reilly's tech really felt like it was the valve cover but that doesn't explain why it'd suddenly come back with the warm weather, I wouldnt think. Thoughts?

 

[r24]

Hey, my dads sonic has the same exact thing, had a p0171, was gone for the winter and now it's back, did you figure it out?

 

[granpajo]

Unfortunately I haven't figured it out yet. Haven't had the time to do some digging or get it to a shop. I'll update if I do.

 

[r24]

Unfortunately I haven't figured it out yet. Haven't had the time to do some digging or get it to a shop. I'll update if I do.

Alright thanks for responding, I'll also mention that we did change valve cover as well as installing the cruzekits pcv kit, and replacing the maf sensor itself not too long ago, so for us it's not that.

 

[Emma’s sonic]

Found these posts in search. Not sure if the issues were resolved and am curious if you don't mind me asking. What was the fix if any? I just replaced both Valve cover and intake manifold but haven't solved the problem of excessive crankcase vacuum.

 

[granpajo]

Turns out, for those looking at this post, that my issue turned out to be a cracked valve cover.