99 s-10 2.2 will not pass CA. emissions test

[sorensic42]

My S-10 will not pass due to hign nox readings. I was told to check the egr valve. I was then informed that the 2.2 was not equiped with an egr valve.
A smog technician believed that the high nox reading may be the result of high carbon buildup on the pistons. Any information related to this or any other possable problems for high nox readings along with advice on how to resolve the problem would be appreciated.

[OverBoardProject]

Welcome to Automotive Forums sorensic42

The best way that I know of to clean out the carbon is steam clean the inside of the motor.

Take a spray bottle, fill it with water, take off the air filter then start the truck.
Now spray the water (you want it on mist) into the air filter opening so that it sucks into the motor. 1/4 to 1/2 a bottle should be enough to have the motor sparkly clean inside.

You probably thought that it would be something that would cost you a mint

[RahX]

The steam clean works great but is tricky because as we all know water isn't compressible and hydrolock is a violent death for an engine :P A far easier and safer way is to pay $5-$6 US and get a can of seafoam from the zone or wherever. It is in a red and white can that says seafoam. There is a seafoam for transmission so make sure its for engines. What you do is put about half of it in the engine through the brake booster line and the other half in the gas tank. Pull the brake booster line, cover it with your thumb and have someone start the truck. Next have them hold the rpm at about 1200-1500 while you pour half of the can in the hose as fast as you possibly can without spilling everywhere. If you go a bit over don't worry too much but make sure you get half the can in there. When you get half the can in there have the person shut the truck down asap and let it sit for 10 mins. After 10 mins start it up (it might be hard to start) and clear it out. Drive it and such also. Now you have accomplished a few things, a clean intake/intake valves/cylinder for the most part and a nice mosquito free neighborhood . The half can in the tank should be part of a full tank and finish off that tank. You should have a squeaky engine after everything is said and done.