Engine Pop when I get on it.

[DrkBluT-TyPe]

I recently replaced the MAF in my Buick, ran it around nice and easy with 93 and went and picked up sup VP Raceing gas yesterday. I put 5 gallons in with less of a 1/4 tank of 93. It ran excelent, but I noticed when I got on it and about 4 seconds into it I heard a POP from the engine, almost like a backfire...I was like...possibly a lean pop or spark plug(s) going out. I ran race gas in it before the MAF went out and it didn't do this. It did the pop 2 more times then I never got on it again. I have Erics chip tuned for 93 with alky and running 22#. I know my 02 Sensor is out, I have another on the way also...any help is greatly appreciated.

EDIT: My car still runs excelent! The POP scares me though...

 

[DrkBluT-TyPe]

MAF went out...again...third one. Maybe that was it. MAFless MaxEffort chip coming in soon hopefully......

 

[ThikStik]

Ive heard of a bad o2 sensor causing this...you know yours is bad, right?