CEL

[charlie03fastGT]

Got these codes P0171 and P0174 any ideas what's causing it to run lean?

[1slosix]

Vacuum leak or gasket leak since both are flashing up...if it was just one or the other id say either leak or faulty sensor

[charlie03fastGT]

Originally Posted by 1slosix

Vacuum leak or gasket leak since both are flashing up...if it was just one or the other id say either leak or faulty sensor

That's my thought cuz the intake manifold just got replaced.

[1slosix]

Id check the gasket ...or was this code flashing before the replacement happened? Did your old intake crack?

[charlie03fastGT]

Originally Posted by 1slosix

Id check the gasket ...or was this code flashing before the replacement happened? Did your old intake crack?

Yes my old one cracked. The light came on like 75 miles after putting the new one on.

[1slosix]

Hmm if it cracked between drive cycles that can explain away the delayed light. Pull the battery for 15 minutes to reset the live data....drive it and see if the lights comes on and stays on after about 75 miles. If it does have it retested and see if the code is the same or shifted

[charlie03fastGT]

Ima vacuum test it tommorrw and go from there.