Any pointers on this query gratefully received TIA!

My Accord was in limp mode with engine management light on. Drove normally upto 200rpm but not beyound. Garage diagnosed restricted egr valve flow, so I took it to bits as much as I could, cleaned it and ran an egr cleaner whilst running the engine. Have filled the tank with Shell V Power and an injector cleaner and changed the oil and filter for 5 - 30W semi synthetic. As soon as I started the car again and since (done about 100 miles ) the engine management line has gone off, the car revs normally above 2000 rpm with great power BUT now does not have anything like the power it did before below 2000 rpm??? Bit mystified as to what I could have done to solve the problem on one hand but reversed it on the other hand! It was very gundged up inside and may take time to clean out but wondering if something else has become blocked during the cleaning process annoyingly? Many thanks

 

WELCOME! but wait, help us out here. I think there's a few things I'm confused about.

The cdti is a diesel, right? (we don't get Honda diesels in USA) Shell V-power? Over here, that's only a petrol; Shell doesn't put that name on diesel fuel.

Since the engine-mgmt lamp is on, you should get the error code scanned. Do they do that at car-parts stores over there? But if you do, I'm not sure the code list is the same for diesels.