96 Mk8 IMRC Delete check engine light solution


I had reproduced the old IMRC delete relay circuit for 96 to 98 Mustang Cobras (which also works for 97-98 Mk 8s.) I was contacted by a guy with a 96 Mk 8 who asked if it could be used in a 96 Mk 8 with the IMRCs deleted. I figured out that it can't, but it is even easier to do in a 96 Mk 8, all it takes is a standard SPDT automotive relay. The 96 Mark 8 owner has validated that it works in his car. Here's the write-up I did that tells you all about how the system works and how to wire the relay if you want to delete the IMRCs in your 96 Mark 8: https://img1.wsimg.com/blobby/go/19...8IMRCDeleteAnalysisR1-2.pdf?ver=1674616658120

If you want to learn how to make the delete relay circuit for the 97 and 98 Mark 8s, go here: https://accutach.com/imrc-delete-relay

Feel free to share this information around the internet.


Head Moderator
Staff member
Nice write up but why would someone want to delete the IMRC's? doesn't that make you lose low end torque? I thought that was the whole reason for the circuit to be there.


The main reason people want to delete the IMRCs is because the valves get gunked up and stick causing a DTC and retarded spark timing. They get tired of having to occasionally take them apart and clean them. Others have trouble finding parts (or don't want to pay) after a failure and need to pass a smog test. Many people report that they can't tell the low end torque loss with their butt dynos. BTW, a custom tune can help compensate for that loss of torque, and eliminates the need for the relay, but custom tunes are also expensive.

I am not advocating that people delete them, just enabling it. I would probably fix it if it were my car...


Lincoln Evangelist
Staff member
Paid Member
Thanks Mark!

I really appreciate you taking the time to post this information here. I'm sure a bunch of folks will find this to be useful.