friend, such stories are always sad. in short, with the engine off, the fan and radio were on for about 5 minutes... and the engine didn't start! so, had to jumper-start it. then after turning off, it re started fine - for almost a month as i did not use the fan/radio on an off engine. and since the engine started easily on the first try (before the battery discharged) i had no problems even in starting in the mornings all this time.
and then i turned on the radio and fan again, on an off engine... and that's when i decided to change the battery! btw, the water level was okay in battery all this time. also, this last month... the dome light used to turn off while starting!
before removing the batter, i retested it... jumper start... turn off... restart ok... turn off... radio and fan on... not enough charge to restart!
if u're talking about the MAF sensor (in the air intake), it is available easily in any good parts shop in khi especially plaza. price can vary b/w 2.5k to 4k. e.g. if u go to prime defence motors and ask him to change it, he might charge 3.5k to 4k for it. but if you go to the shops yourself, you might be able to get it for a bit less. easy solution is to go to a good place and let him find the sensor even if u have to pay extra 500 or 1000 as it'll be his responsibility to fix the problem. do let us know the outcome! and yes, i have cng kit installed.
good to hear that!