Piping error with extra line and does not give a header - powershell

Question

0001;Third Week;Every Monday 12am-2am
002;Third Week;Every Tuesday 8pm-10pm
003;Third Week;Every Monday 12am-2am
#Get the number of lines in a CSV file
$Lines = (Import-Csv "C:\MM1.csv").count
#Import the CSV file
$a = #(Import-CSV "C:\MM1.csv")
$month = Get-Date -Format MMMM
#loop around the end of the file
for ($i=0; $i -le $lines; $i++) {
$Servername = $a[$i].ServerName
$week = $a[$i].Week
$dayweekString = [String]$a[$i].DayTime
# This will help in getting the Day of the WeekDay String
$dayweekString = ($dayweekString -split "\s+",(3))[(1)]
#This will find the time Ex 2am or 8pm, it can be any time
$DayNew = if ($Day -match "\d{1,2}Travelm") {$Matches[0]}
#Format for Maintenance mode which can be fed into the SCOM MM Script.
$MaintenanceTime = get-date "$DayNew $month.$($_.$dayweekString).$year"
write-host $Servername, $MaintenanceTime
#Store all my data while in a for each loop
New-Object -TypeName PSObject -Property #{
ServerNameNew = $Servername
TimeStamp = $MaintenanceTime
} | Select-Object ServerNameNew,TimeStamp
} | Export-Csv -Path "C:\MM3.csv" -Append
# Error as extra Pipe
I am not able to pipe the output while in a loop with a header. Says Extra pipe and writes a extra line of TimeStamp Variable to the line.

Answer 1

You are trying to pipe the result of the for statement to another command. That's not supported. If you want to do that, you need to use a subexpression around the statement:
$( for(){} ) | ...
(The reason is that pipelines need an expression as their first element. And for is not an expression, it's a statement.)
However, in your case I'd replace the for with a simple pipeline iterating over the array, like this:
Import-CSV "C:\MM1.csv" | ForEach-Object {
$Servername = $_.ServerName
$week = $_.Week
$dayweekString = [String]$_.DayTime
...
}
Generally there is very rarely a reason to use explicit looping constructs in PowerShell. It leads to code that's awkward at best (because it resembles converted C# or VBScript code) and horrible at worst. Just don't do it.