This works 
<Location /perl>
  SetHandler perl-script
  PerlResponseHandler ModPerl::Registry
  Options +ExecCGI
  PerlOptions +ParseHeaders
  PerlOptions +SetupEnv
</Location>

#!/usr/bin/perl --
use strict;
use warnings;
use CGI;
use Data::Dumper;
Main(@ARGV);
exit(0);
sub Main {
    my $cgi = CGI->new;
    print $cgi->header(  -status => 404, -nph => 0, );
    print $cgi->start_html,
    $cgi->b(rand time, ' ', scalar gmtime),
    print '<table border="1" width="%100"><tr><td>',
    $cgi->Dump,
    '</td><td><div style="white-space: pre-wrap; overflow: scroll;">',
    $cgi->escapeHTML( Dumper( $cgi ) ),
    '</div></td></tr></table>',
    CGI->new( \%ENV )->Dump;
    print $cgi->hr;
    print
    $cgi->end_form,
    $cgi->end_html;
}

[download]
This works 
PerlModule Apache2::Hello404
<Location /hello404>
  SetHandler perl-script
  PerlResponseHandler Apache2::Hello404
</Location>

package Apache2::Hello404;
use Apache2::RequestRec;
use Apache2::RequestIO;
use Apache2::Const -compile => qw(OK NOT_FOUND);
sub handler {
  my $r = shift;
  my $package = __PACKAGE__;
  my $req = Apache2::Request->new($r);
  my $val = $req->param('key') || '';
  my $msg = $val ?  qq{You passed in a value of "$val" for "key"} :
    'No "key" parameter was passed ';
  my $time = scalar localtime;
  $r->status(Apache2::Const::NOT_FOUND);
  $r->content_type('text/html');
  $r->print(<<"END");
<html>
<head><title>$package handler</title></head>
<body>
Hello from $package. It is $time.<br />
$msg
</body>
</html>
END
  return Apache2::Const::OK;
}
1;

[download]
Using $r->status() is key

In reply to Re^4: mod_perl give 404 not_found with content by Anonymous Monk
in thread mod_perl give 404 not_found with content by Jaap

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.