If you added the bolt-ons for more Hp you probly will need to do more than that depending on the ECU. What happens at least in the OBDII is that whenever air and fuel ratios are modified the computer will recompensate to return the setting to OEM(most economical). So unless the ECU is instructed to via: chip, or plug n play system you really won't feel a differance. My advise GET A CHIP!! The venom 400 is hot and so are JET chips. I have a plug n play system I use with my laptop by Apex and I can change and modify ratios all the time to find peek performance. BE ADVISED the cheap chips on Ebay are a joke don't waiste your money