97 Bravada P1406

We bought our Bravada about 6 months ago, took it to Florida, has 154,000 miles on it. #1- Now, it is so slow and hesitant. Trying to take off is such a chore for it. It has no power up hill, even goes from 50 to 30mph within 5 seconds. Attached the OBD II and it displayed P1406. We changed the EGR valve and still the same. Changed the spark plugs and wires as well. Still the same, no power and alot of jerking. #2- It has begun to overheat. It has a black sludge in the radiator. Flushed it, new thermostat, still hot. Lasts about 15 minutes of driving and have to stop. Don't know what the black sludge is but when we flushed it, it ran clear.
Anyone know what to do next? Any suggestions would be greatly appreciated.

Welcome to AF.

On the egr valve pull egr valve and look for carbon ball under plunger.

Then check for engine miss and why it is missing.

We bought our Bravada about 6 months ago, took it to Florida, has 154,000 miles on it. #1- Now, it is so slow and hesitant. Trying to take off is such a chore for it. It has no power up hill, even goes from 50 to 30mph within 5 seconds. Attached the OBD II and it displayed P1406. We changed the EGR valve and still the same. Changed the spark plugs and wires as well. Still the same, no power and alot of jerking. #2- It has begun to overheat. It has a black sludge in the radiator. Flushed it, new thermostat, still hot. Lasts about 15 minutes of driving and have to stop. Don't know what the black sludge is but when we flushed it, it ran clear.
Anyone know what to do next? Any suggestions would be greatly appreciated.

I strongly recommend a Reverse Power Flush on the cooling system. You should be able to get this for $50 - $75 US.

It sounds as if you are possibly starving for gas, have you changed fuel filters? You might want to check your fuel pressure.

Sorry, I am not good with codes, but the basic maintenance might just do the trick.

A fuel pressure check kit is available at your local auto parts store. This is where it's connected.
http://i131.photobucket.com/albums/p288/Clunk_/Image026.jpg

My :2cents: egr code,no power,over heating, I think I would check the catalytic(?) converter.