friends, i would need advise on how to solve the performance issue on my acura mdx 2001 model. when moving between 20-50 miles, it stutters and vtm-4 engine light comes up. I scanned and the code i got was P1491 (EGR Valve Insufficient Lift). i have done the following but the engine still hesitates:
1. I have changed the EGR Valve
2. I have cleaned the clogged ports on the manifold
3. I have changed the spark plugs and changed oil + filter
4. introduced injector cleaner into the fuel system. i had cleaned the injectors

what else can i do? any body in lagos had similar issue and how was it resolved?

awaiting your responses