I’m curious does removing the restrictor out of the hose cause a high idle on cold start ? I’m having the same issue which is p0401. So far tested and cleaned Egr valve, replaced solenoid with a dorman brand , and I replaced the restricted hose with a regular one . Haven’t got a CEL yet but I’m worried that it may be damage engine internals in the long run . Any thoughts or opinions would be greatly appreciated. Btw Cel stayed on after Egr valve clean and solenoid replacement but stayed off so far with the restrictor hose replaced with a regular one .