CM870 tuning

[Rawze]

(06-27-2026 )Magnat1976 Wrote:  ...
Yesterday I tried the trick, I hooked the an extra egr valve to the harness to cheat,it drives,but I am getting delta p sensor -value too high error..is it clogging?...
About Egt I put pro on exhaust manifold, not inside..and dont have hills

There is no need to "trick" it ... that is a bunch of horse-malarly. The CM870 ecm programming already has an EGR-off mode built into the factory programming. - All anyone has to do to put a CM870 into its proper no-egr operating mode (assuming this is for troubleshooting purposes... ehemm), is to unplug the EGR temperature sensor (and leave everything else plugged in properly),.. located in the egr piping somewhere near the fuel filter area. The ecm will shut off the egr system and close the valve for you if you simply do that. The CEL will be on for the unplugged sensor, but it hurts nothing whatsoever. I have seen people run them that way for a million+ miles, engine is not going to shut down over this. - It will have a boost derate, but not a power derate when in this condition. Boost will spike to about 36, then fall off to about 32 psi and hold there. POWER will NOT be lost due to this. - This is normal when egr is off on factory programming and no one has adjusted ecm it to stop the slight boost derate.