Changing imei on mtk chipset

note 1 : I don't know if you have to root your phone but mine was rooted.
note 2 : Most of the Chinese clone phone the 1st Sim which is a 3G will work perfectly. Only the problem happens when we insert the second sim. If you check you can see the IMEI of 1st sim will start with 35xxxxx and the 2nd will start with 88xxxxxxxx. That is why the second sim is not able to register to the network, because its not in international formatted IMEI. So usually we need to change the IMEI of phone 2. There is no illegal purpose on this.
note 3 : I didn't tried method 2.

Method1

I read another method but this is also worked for mine.

1. First download mobileuncle tools from google play.
2. Open mobileuncle and enter Engineer mode(MTK).
3. Under telephony title you'll see GPRS. enter that.
4. You'll see imei number there. As sim1 and sim2.
5. Write the imei as you want and touch write imei.

 Geçersiz: Invalid in Turkish.

Method 2:

1. Open Mobileuncle tools.

2- Select Engineer mode[MTK]

3- Go to CDS information

4- Select Radio Information

Here you can see Phone1 and Phone2, 

5-Select which you want to change imei.

Here you can see a command line with “AT+”. If you want to change sim2 just add this command to it

AT+EGMR=1,10,”15 digit YOUR NEW IMEI NO”

And press “send at command” button. 

[ if you want to change the the phone 1 IMEI AT+EGMR=1,7,”NEW IMEI NO”]

MTK 65## GPS problem

Unless there is problem with your gps antenna, you can able to use your GPS more faster than before!

1. First root your phone.
2. Download "root explorer" and open root explorer find this path:
data\misc\mtkgps.dat

3. Delete this file. Restart phone.
5. Download "Faster GPS" and open it. Set your home country same as in the picture.

4. Download "Mobileuncle Tools " and open Mobileuncle Tools
5. Find engineer mode. Open Engineer Mode (MTK). Under the Location title:
5.1 open Location Based Service. make sure your Enable A-gps and  enable epo is marked. Alsa mark Auto Download on EPO.

5.2 Press back button once and open GPS function. Enter YGPS. After couples of seconds(mine was 7) it catches the satelites.

But there is a huge problem that, When I try to save my track, it show unreliable speeds and distances. But shows you the place you are. 

MTK based gps chips are worse. If you are thinking of buy this stuff think again. Do not buy MTK based phone or tablet!