+1 on the seafoam.
I was lucky when I bought my car in that the original owner had done regular oil changes.
I started the Seafoam right away with some in the gas, some up the brake booster vacuum line and a full can in the crankcase oil. (but I saved some for my gun)
I dumped the oil 100 miles later and it came out VERY black.
The second time it came out black and now after using it every oil change my oil comes out almost the same color as it goes in.
I put it in my oil now AFTER my oil change and run it for 3000 miles then change my oil again (with the cheapest oil I can find on sale at wall-mart).
I believe the seafoam has made all the difference.
I don't burn a drop of oil and I'm certain my internals are clean,.. including those damn tiny drain holes on our pistons.
The last time I had my tail pipe sniffed for Emissions the guy said he thought his machine was screwed up,... I had lower emissions than when the car was new.
My original EGR is still on the car and has never been a problem. (They re-invented the EGR just for us Canadians.)
I figure with my emissions as clean as the air it sucks in, there's no crap in my exhaust to foul my EGR.
(Yea I know,.. now I gotta go buy a 1/4 stubby,.. or find some wood to knock on)
I keep a can in the car and put a shot in the gas every tank or two (ten treatments.... tens bucks... good economy for for an "injector cleaner").
As soon as my idle starts to stumble a few shoots go in the brake booster vacuum line then 1/3 of a can in the gas after I drop below a 1/4 tank.
Keep in mind that if your car has never been done, you could have ten pounds of sludge built up inside your engine and your oil could turn into pudding.
If your car is REALLY bad (a turd) then you could be washing away the stuff that keeping your seals sealed,... then you could spring leaks like a Maple tree in the spring.
Then you need to put thickeners in to plug them back up again ( or just shoot the car,... it's probably time,.. )