Columbia long start, loss of power and decreased fuel economy.

You said you have an EGR code. That needs to be investigated, that is where the problem is.
Let’s have a look at some of the common signs which point to a failing EGR valve:
You have all 5 of these.
1. ROUGH IDLE
Any change in RPM at idle should be cause for concern. A “sloppy” or rough idle can be caused by one of several things. One of the reasons that your truck may have a rough idle is due to a defective EGR valve that is stuck in the open or closed position.

2. EXCESSIVE SMOKE
Modern diesel engines produce next to no smoke. Coal rolling, locomotive-like engines are now a thing of the past. Any signs of excessive smoke should be taken note of and investigated as soon as possible to avoid further issues.

3. INCREASED FUEL CONSUMPTION
If you spend hours behind the wheel each day, chances are that even the slightest increase in fuel consumption will get noticed. One of the first things to check is the EGR valve. A defective exhaust gas recirculating valve could be the culprit.

4. DECREASED ENGINE PERFORMANCE
Does your truck feel sluggish? Does it not have the same amount of acceleration as it once did? Something as simple as a defective EGR valve could be to blame.

5. CHECK ENGINE LIGHT
Cars, trucks, tractor-trailers, and almost anything else with an engine that is on the road today will have some sort of ECU controlling all the parameters to make sure everything is in good working condition. If your check engine light comes on, the best thing to is to have the codes scanned to fully determine the issue.