Try to theme a specific page using template.php and a sub theme I have a theme called 'progressive'. It has a sub theme called 'progressive_sub'.

I'm trying to exclude items from being displayed from a particular page in D7 (latest as of 12.2.15).

I have the following useful files:

/sites/all/themes/progressive/progressive_sub/template.php

This contains:

&lt;?php

/**
 * Implements hook_preprocess_page().
 */
function progressive_sub_preprocess_page(&amp;$variables) {
  $path = request_path();

  if ($path = 'node/131') {
    unset($variables['page']['header']);
    unset($variables['page']['sidebar']);
    unset($variables['page']['footer']);
    unset($variables['page']['bottom']);
    unset($variables['page']['top']);
    unset($variables['page']['content_top']);
    unset($variables['page']['sidebar']);
    unset($variables['page']['bottom']);
    unset($variables['page']['footer']);
    $variables['theme_hook_suggestions'][] = 'page';
  }
}


You can see that I'm trying to remove a heap of regions from this page (page.tpl.php) template, in this case when /node/131 is called.

I also have:

/sites/all/themes/progressive/progressive_sub/templates/page.tpl.php

which has all the usual including:

&lt;?php print render($page['content']); ?&gt;


My problem is that I cannot get this page.tpl.php to load when I'm viewing /node/131

Is there something that I'm doing wrong?
This 

if ($path = 'node/131')


should surely be

if ($path == 'node/131')


Nevertheless this should not affect use of page.tpl.php.

Is your subtheme working at all, do templates get loaded from subtheme at all?

Your path is /sites/all/themes/progressive/progressive_sub. Does that mean the parent theme is at /sites/all/themes/progressive? If so, maybe try to give the subtheme a separate folder.