Yes, if you want to benefit from having this (Traditional) IRA, your income needs to go down. Reducing your income via 401(k) contributions is an easy way to do this, so long as you can handle the reduced income in your paycheck.
In order to get a full-benefit, you'd have to be contributing A LOT more to the 401(k). Is this worth it?
To get a full deduction, you'd have to have MAGI at or below $62,000 in 2017. Otherwise, you are still looking at a partial deduction. If you contribute $2000 to the IRA and get a $1500 deduction, you might save $375 on your taxes. And have thousands less in your take home.
https://www.irs.gov/retirement-plans/2017-ira-deduction-limits-effect-of-modified-agi-on-deduction-i...
