about a month ago car started having the chirp under the hood. narrowed it down to it being a lifter going bad & car would need a dod delete. a comp cam premium dod delete kit was purschased & i took the car to a local performance shop. Keep in mind that at the moment the only issue the car is having is the chirp under the hood. transmission is fine. car runs great no issues. Also the car is remaining stock. im not adding any mods, just getting the dod delete. fast forward a couple weeks. i get my car back. dod delete was complete. afm was turned off. no tune. just turned off the afm. now my car is having random misfires (P0300) & apparently the transmission has started to slip, which when i come up to a light & come to a stop the car wants to stall & turn off but stays on. Any ideas? does the car need a complete tune? Transmission reprogrammed/reflashed? what could be causing this?