After converting to SD (Evo 6, Ceddy's SD) I've been experiencing severe jitters/stutter up to 3500rpm. Ceddy's SD is not known to have a jitters issue! Logs show that map & iat sensors are working fine, ipw readings look fine too. One clue is that the problem is less severe if iat sensor is disconnected!
Any tips how to trouble shoot such issue or how to remedy it?

 

Are you on stock injectors ?

Check out the scaling for IAT sensor.