Sorry for my bad english.
do not delete this post please, I understand very little English, and I find it hard to find information via search.
My name is Roman, i am from Russia.
I take Imoreza WRX Wagon from Japan (GGA-003042) right-handed/
Them i am install some goods (blow-off, exchaust,fuel pump walbro and more litle upgrades)
After that my car was going worse, I think that the mixture has become oversaturated with air. Poor mixture.
In my country, only three places do chip tuning, and all three places are very far from me.
I decided to try it yourself but the Russian-language forums, so there is no information.
If you tell me step by step what should I do, I'll be very good.