0 like 0 dislike
796 views
by

The check engine light was on, so could not smog. I took it in to have it fixed and the truck read the following codes. P0446, P0463, P01637, P1638 The mechanic "checked the alternator"
reporting it was ok. He did circuit tests for fuel senser and EVAP. He then replaced the fuel modual, cleared codes and reported they did not come back. Shortly after that the service engine light came on again and when scanned said P1637 & P1638 again. He said to bring it to a different place and have alternator checked by someone who could do a more thorough job. Had it checked and it was ok so cleared codes and comepletsolstice cycle. Now the truck will not cimete the EVAP or the secondary air system cycles!!! HELP!!

Vehicle: 2001 Chevy Silverado 1500 5.3L V8

1 Answer

0 like 0 dislike
by (13.4k points)
Inorder to complet the EVAP cycle the fuel has to be more than 1/4 and less that 3/4. The secondary air will need a 2nd drive cycle, which means the vehicle must sit till a cold start, until the catalytic monitor runs the EVAP will be the last to run.

Related questions

0 like 0 dislike
1 answer 1.4k views
0 like 0 dislike
1 answer 364 views
1 like 0 dislike
2 answers 3.3k views
1 like 0 dislike
2 answers 293 views

36.2k questions

32.2k answers

1.3k comments

22.8k users

Need A Repair Shop?
Find local automotive repair shops in your area.
Does your car have Safety Recalls? → Check here
...