Hey i tried a lot but just couldnt get this done...the problem is 

 

 

1> The E key on foot for cite/hold/frisk does not work always i tried re installing but its just not working

2> Its irrelevant but the UP arrow key to start the cell phone in game also doesn't work sometimes 

 

 

Please I would really appreciate if anybody helps me!!

Are you using simple native trainer? If so, disable the trainer keys (Options (F3 or F4 > Disable/Enable Trainer Keys). 

No Sir i am not using simple native trainer but i do not face the problem with some models of the police

Sometimes when I get low FPS in certain areas in the Liberty City, keys like E for cite/hold/frisk peds doesn't respond fast then I have to slowly press it few times for it to respond, or the ped you are trying to cite/hold/frisk is glitched and is not responding to your commands. Maybe that is why the E key is not working sometimes and the phone is probably not appearing because of the low FPS unless you have good computer then it's probably something wrong with the game or the key on the keyboard.