Hi, I'm having a similar issue... Can we not just insert the pixel code into the CSS for each page? I'm not a developer so excuse me for my ignorance. Or does it have to go into the functions.php file to be inserted into the header?
Here's what I'm using, but with the Facebook Pixel helper it's showing that there's an error in the code...
/*Pixel Event Code*/
if (is_page(202) ) : ?>
<img height="1" width="1" style="display:none"
<?php endif; }
add_action( 'wp_head', 'fb_print_pixel_event' );