strange O2 voltage readings

[TD05HTalon]

ok here's the situation. my o2 voltages are normal both with my digital gauge and pocketlogger while cruising or accelerating. the problem comes when i let off the gas. my o2's go really rich for a few seconds then turn more lean. i don't understand why i would get a rich mixture when decelerating. the car sputters and the engine hesitates while the o2's are rich but feels normal after they level off.

 

[LightningGSX]

Without further info or examining your vehicle, I would say this is normal.You shouldn't put much thought into your o2 readings anyway.The rich indication on your gauge doesn't mean you are actually rich, outside of stoich, your exhaust temp influences your 02 gauge more than your fuel mixture.

 

[TD05HTalon]

it's not the o2 voltage that 's really bothering me. it's when i let off the gas the car shudders and backfires for about 5 seconds. i just checked my datalogs and AF gauge and both show that the car is going extremely rich at that time too. it's like i'm dumping a ton of fuel when i let off the gas which wasn't happening a week ago.