Got code 26

Where is it located and could it be turning off my car when I go foward because on reverse it runs fine but when I let the clutch go gently it runs but if I put it 1/4 throttle open it shuts of

I changed the egr valve once but it was used so do I replace it but the car makes like a poping bnag noice could it be it ill try it to see what happens thankx for the tip

Now I got a new code it's 42 bypass circut open or shorted from ignition mudule to PCM how can I scan it