If replacing the MAF and adding a translator is causing your codes according to what you stated in your first post then the issue to look for would start there.
Did it run OK before you replaced the MAF and translator ?
Are you sure its a 3.5" and not an LT1 3" or an 85mm ?
Did you orient the MAF in the correct direction of air flow. There's an arrow on the MAF pointing the true direction of flow.
If you installed a new chip at the same time you put in the MAF as previously stated above... check for bent pins on the chip.
"Quoting TT Eric" Also, check the ECM chip socket for any pins that are bent in too far, possibly making poor contact with the chip. The ECM socket pins can be carefully bent back out with a pin or needle.