Re: EGR cleaning.
About any actual cleaner works.
I forget the name of them, but I would take one of those little wire pipe cleaners we all used in elementary school for arts & crafts & clean it out by hand.
Vacuum leaks, check the timing & ignition components.
Use a spraybottle of water to spray into a large port like the brake booster port. On a warmed up & running engine, pull the brake booster port & hold the spray nozzle on the port so it doesn't stall from the large vacuum leak. Spray away... If you spray real fast you can get the engine to slow down. That's pretty much what you want. By the time you get through a 16oz bottle, the combustion chambers are going to be a few times cleaner than they were before.
(Make sure it's a mist. A stream isn't going to do anything)
That's a great free way to clean carbon off the intake valves/combustion chambers.
2 $5 cans of Seafoam are a Godsend. 1/2 a can in with fresh oil, 1/2 a can when you stop to fill up the gas tank. The second can you want to suck/pour 1/3 of a can into an engine port (like the brake booster, or PCV line) with the engine running. (Obviously it will want to stall).
Immediately turn the engine off & let it sit 10 min. When you crank it it will billow smoke. Let it idle for about 10 min until it's smoothed out a bit - then drive it around until it stops smoking. While you drive around, hold it in gears a few times and let it rev up through the redline to make sure you burn everything out.
You want to do a full can like this.
And no, you have no idea what billowing smoke means until you see a warm engine burning carbon & seafoam. Just idling is enough to fill a few city blocks if it's *really* bad LoL!.
People ask what's the difference. Seafoam works better, but water will get more of the coated carbon out of the combustion chamber.