pinging and hesitation problems, could it be my maf?

i just installed a 76mm C&L Maf and inlet pipe......i currently had a upr fenderwell cai....i was expecting a slight gain in power, but that was hardly the case. it seems that the car has lost some power, it doesent rev and accelerate as quick as before. and now the car pinges when you get on it. im also getting some hesitation, especially at the low rpm's. i give it gas, it hesitates, then it backfires through the intake, AND THEN it starts pinging!!! im wondering if its becuase the filter is now inside the engine bay. my engine gives out ALOT of heat....oh yeah and i just replaced my maf sensor cus it went bad.....anybody know whats wrong with my car???

well....put my old upr cai back on and i rotated the meter slightly clockwise, and now the filter was outside the fenderwell.....it runs fine now with no hesitation, no pinging and no backfiring through the filter.... i did notice i slight bit of power loss. im guessing this is natural since my induction is still stock(tb,manifold,heads) i also like the upr cai better than the c&l inlet pipe since its just a straight pipe. i dont like the bend the c&l pipe has. to me, that bend looks like it would hurt air velocity, wont it? am i really lossing alot of power with just the meter and no other induction help? thank guys