2003 Dodge ram1500 converter question

[Red Ramdd]

I am installing a 2005 5.7 hemi in my 2003 in place of its 5.7 hemi my question is if I take the catalytic converter off and run without it will it set a code off and then turn on the check engine light. I might go to dual exhaust if it doesn't cause a problem. Thanks Don

 

[HemiLonestar]

Yes it will, not sure if you can have it written out in a custom tune on an 03 (limited tunability) or not. Also don't forget to plug the EGR hole in the passenger side cylinder head and the intake manifold (or reuse your 03 manifold).