99-04 mustang ls swapped check engine light
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Teching In
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99-04 mustang ls swapped check engine light Finishing up my build hopefully this weekend finally! Car is a 6.0 lq4 ls3 top end i need to get the car inspected eventually and i got almost all the lights out. Check engine light is on because of all the ford sensors not being plugged in. Car is running on a holley terminator x system. Do I need to figure out how to wire in the ford wiring into the sensors for the Chevy or is there any way I can jump some wires together to trick the car?
Thread Starter
Teching In
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Yes it does sadly. Emissions and safety. Emissions until 25 years old car is a 2004 so i got a couple years until it doesnt need to pass emissions anymore. Im in the northeast and was thinking about registering it in another state up north tht doesnt do the inspections if it comes down to it. Would like tht to be the last option
On The Tree
Joined: Mar 2010
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The only way I could imagine is to leave the factory engine computer in the vehicle & scan it to see what it is missing. Retrofit the Mustang sensors to the LS engine to make it believe the original engine is still there.
I did this on my Jeep to make the factory cluster work. Maybe one of the Holley gurus can chime in to determine if the Terminator outputs could be used to fill in for missing sensor outputs like crank sensor.
Lastly, if you have some faults that can't be solved maybe have the original computer tuned to shut off the faults.
I did this on my Jeep to make the factory cluster work. Maybe one of the Holley gurus can chime in to determine if the Terminator outputs could be used to fill in for missing sensor outputs like crank sensor.
Lastly, if you have some faults that can't be solved maybe have the original computer tuned to shut off the faults.
Last edited by nleming; Nov 8, 2025 at 05:55 PM.
Thread Starter
Teching In
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Yeah thts what I was thinking also. I can get it tuned to turn off the monitors and stuff like evap, o2s, egr. Only thing I can think is cam, crank, ect. That i would have to figure out how to get to work
On The Tree
Joined: Mar 2010
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@Project GatTagO is the Holley guru. I'd assume the Tach output could be used to replicate the crank sensor. He might be able to tell you if it can output a cam sensor signal.
You will probably have to turn off tons of faults to even hope this could work. It will probably be looking for misfire and all sorts of things. I'm not sure how "smart" that computer is.
You will probably have to turn off tons of faults to even hope this could work. It will probably be looking for misfire and all sorts of things. I'm not sure how "smart" that computer is.
@Project GatTagO is the Holley guru. I'd assume the Tach output could be used to replicate the crank sensor. He might be able to tell you if it can output a cam sensor signal.
You will probably have to turn off tons of faults to even hope this could work. It will probably be looking for misfire and all sorts of things. I'm not sure how "smart" that computer is.
You will probably have to turn off tons of faults to even hope this could work. It will probably be looking for misfire and all sorts of things. I'm not sure how "smart" that computer is.
Andrew
