If SeaFoam is not thoroughly cleared out of the system (intake, fuel, oil) could it have adverse effects on the outcome of an emission test?

 

Probably not. I will not use Seafoam other than in my gas tank if ever for just that reason. If there are deposits, chances are they are filling in the imperfections that have surfaced inside your engine over the years. If you remove the deposits, then you can get leaks, and other adverse affects.

 

It wouldn't worry about any seafoam in the oil, unless there was liquid goo draining into the engine during the testing, I wouldn't really worry about that either. If it were in the gas tank, I imagine it wouldn't cause harm as it should burn cleanly.

As long as its been more than maybe 20 miles (just a guess, probably less) since you put the seafoam in your intake, you should be fine.

 

thanks for the replies guys. I was just giving the obvious examples. I'm not going to run SeaFoam in the oil, I probably will in the intake and for sure in the gas tank. Its for an '88 22re 4runner Im buying tomorrow that passed emissions except for the air injection system is not working properly. I was thinking, since there was a ton of black junk in the TB/intake Plenum (? The boxy thing behind the TB) that maybe if I were to clean it out, the faulty PAIR might not be noticeable. I was thinking maybe less carbon in the engine= less carbon out the exhaust

But then I was thinking.."Oh they probably actually checked the PAIR system itself to see if it was working" So really, I think I just need to work on that.