I would try seafoam. My problem wasn't the same as yours. I had a real bad spark knock and it was a dog. I ran I think a 1/3 can through the intake and a whole can through the tank. That was over a year now and I haven't had any spark knock. Might be worth a try. If you do the intake don't just dump it in. Pour it slow so it gets sucked in. the engine will want to die but keep the rmps up a little to keep the motor running the shut it off and let it sit for 15min. It may start hard I thought I screw the motor up because it wouldn't start. Once it starts though it will smoke and stinks bad. It works good.

 

so the truck is inspected for another year. ugh. 398 dollars later. so they replaced both o2 sensors and the cat and all the piping. no direct fit or it would take a while to get it back. but the truck was running rich for quite a while i guess. the o2 sensors were melted inside the piping. and the cat had burn holes and was melted almost all the way around the inner edge. so wow that thing must have been running quite hot for a while for it to do that.
but havent gotten the seafoam yet. going to do it thursday after i get it back from the dealer, from getting those 2 recalls checked.
thanks for all the info guys. hopefully ill be able to get that cleaning done without any harm to my exhaust. seeing as how it is completely new from the headers to the tailpipe now.

 

be careful about doing seafoam it has been known to burn up oxygen sensors (the heavy smoke can contaminate them and block them from reading properly) and can potentially damage cats, it is usually recommended to do that BEFORE replacing any of these parts.

 

I've watch people on youtube use seafoam and thier vehicles smoke a lot more than mine did. Which makes me think they used more than the can says to use.

 

or their engines were alot more neglected than yours.

clean engines will smoke less because the smoke you see is carbon deposits burning out of the engine because the chemicals are breaking them down and blowing them out. if you do alot of highway driving there will be alot less build up in your engine than in the engine of someone who does all around town driving.

 

never thought about that shrpshtr. I've only used it once. I figured if its not spark knocking then everything is clean.

 

you know its funny that you guys tell me that now, cuz 2 days befor i did the seafoam trick, i had to get my truck inspected and it wouldnt pass, it turns out that my d was running so rich that it melted the inside of my cat and melted the heads off of my o2 sensors. so i had to pay close to 400 bucks to get them all replaced. so i just got a brand new cat and o2 sensors put on 2 days befor i did the seafoam trick. and oh my god!! it smoked so bad!!!!! i took my cold air off and used a spray bottle to squirt the fluid in the t.b. it smoked for a good 4 to 5 minuts. mean while i had my wife inside the truck keeping the rpms at around 2500. but after that it purr'd like a kitten. it starts up smooth and drives alot nicer. still needs some tlc. and i still need to put about 2 g's worth of work into it mechanically. but ill get all fixed up. wow. this d has turned into something else. if i hadnt bought it when i had. it would have gone to the junk yard for sure. but shes my frankenstien.