So I decided to try seafoam on my car. It was running a bit sluggish lately so I figured what do I have to loose right...Some background on the car, it's a 98 Hatch with about 80k on the chassis and about 74K on the swap. It's daily driven, auto-X'ed and tracked.

So, I went over to my friend's house for this little experiment. We put about half of the can in the intake manifold and the other half in the oil. Did a little "Spirited Driving" and came back to change the oil. After changing the oil I went to start the car back up and it felt a little weird, but I didn't pay much attention to it. About half way out of the neighborhood the car sounded like it was misfiring, I was also low on gas so I was blaming the misfire feel on low gas. I filled up and cranked the car car over and still the same misfire sound. So I drove it less then half a mile back to his house. We pulled the spark plugs and they looked like they where fouled from the seafoam. SO I bought new spark plugs, cap, rotor, and wires. I had wanted to change them anyways. Replaced them and no luck car still misfired, I figured maybe it just needed a little bit of driving to blow some of the seafoam residue if any out. I drove it to the parts store, about 5-6 miles. I bought a PCV Valve, put it in in the parking lot and voila! The car was running without any hesitation and no misfiring, it even sounded like it normally does. Drove it back and it was fine until i got back in the neighborhood then it started acting up again. We pulled the plugs and it looked like it was running lean. After a couple of phone calls to pick some brains it seems like the o2 sensor was the culprit. I called the parts store and they wanted $249 for one!!! After reading online someone said something about their o2 sensor getting clogged up and they cleaned it and it worked fine after that. So we took off the o2 sensor and dipped the tip in some seafoam for about 5 minutes. When we pulled the o2 out of the seafoam it looked like new. Screwed it back on and everything works fine so far. The car seems to idle, and rev a lot smoother.

I hope this helps someone out if they seem to run into the same problem.

Cliff notes: Seafoamed the car, gunk seafoam freed up got on spark plugs and o2 sensor. Car ran like crap, replaced spark plugs and cleaned o2 sensor tip with seafoam, car runs like a champ now.

 

good idea with the o2 sensors. I wonder if you could do that to all o2 sensors to add life to them. Probably a good idea to do that once in a while then.