Try to download istation and comes up with error 491

there are many problem created in google play , i think this blog is useful for you... https://www.errorcodeexpert.com/how-to-fix-google-play-error-code-491/

sc 491 is error signal is detected for 0.2 seconds when charging the drum or development.
• High voltage leak
• Broken harness
• Defective drum unit or development unit
• Defective high voltage supply unit

Mate same with me, I tried to uninstall some of my google factory settings but my phone wouldn't let me so I stopped them from updating and after a while I started getting an error code 491 when I tried downloading apps from google play store. I googled 491 and found this link that showed me how to fix it, If it starts happening again then just repeat this link....CHEERS..
http://android.stackexchange.com/questions/83432/downloading-from-play-store-gives-error-491

The bike is no longer sold and the company went bankrupt in 2014, so neither support nor parts are available from the company. Try the results of this Google search regarding the E1 error code:
fitness quest edge 491 e1 error Google Search

I’m happy to help further over the phone at https://www.6ya.com/expert/donald_f2ed37026a3ac881

Have a look here:
http://www.galaxys4forums.net/forum/4-new-member-introduction-site-assistance/1457-solved-error-491-cannot-download-update-nothing-google-play.html

Grts,
Bart

Try download here:

http://www.retrevo.com/search/v2/jsp/mytrevo/myTrevo.jsp?page=man

install Istat (google it, get the one that's for the menu) to monitor your cpu temps and fan speeds...when you notice they start maxing out, open up activity monitor and see what is eating up your CPU....you must have something in the background running that is causing the CPU to max out...if that's not the case then you might have a defective logic board. ------- check for start up items. thn check with activity monitor CPU and RAM usage, if its okay then check your hard drive with 3rd party programs to see if its failing. ----- Have you tried resetting some of the low level hardware?

System Management Controller (SMC):
http://support.apple.com/kb/HT1411

PRAM and NVRAM:
http://support.apple.com/kb/HT1379

Other thing to look for might be temperature (install iStat Menu and/or iStat Pro) from iSlayer.com. -----
This will help. Thanks please keep updated.please do rate the solution positively .thank you for using fixya

I accidentally formatted my istation and its now requesting for recovery cdrom what can i do and i don't have any cd with me?

You say you have checked properties etc but have you selected mp tray from printing preferences in the driver. Remember the driver overrides the printers own settings.