Damn code 51/31

[Supra Saiyan]

So I figured out that a code 31 can cause a code 51.. Atleast thats how it seems after researching several forums. anyhow, I changed the afm and the tps. Both for another used one. So, NOW.. Only sometimes now the car will die when I stop. I think it's the AFM.. I get a code 31 when I drive around..! DAMN!! Then other times when I reset the EFI fuse.. I drive around and get a code 51.. The same result with dieing when I stop..

So I was wondering if I should replace the metal housing as well as the AFM??

Also, any comments or ideas other than my question..

I'm thinking of trying another AFM..

When I put the old one on i start up and just.. Poof.. DIE!
When I put the newer one on.. I get the issue with dieing much less..
THEN...
I put the old AFM on there, it dies more..
So I put the newer one on and it dies less..

ARRRRGH! I am going to replace the AFM, then the TPS.. Again, questions? Ideas..

btw - I used proper years for the afm and tps.. my car is an 88 turbo..