zeroptzero

I went back to the stock cat as I just put on a Mugen exhaust, I don't see the white smoke with the new setup. It seemed much more prevalent with the HFC (which is almost the same as a test pipe, and just as smelly )

Mine first started when I switched to the HFC, and it seems to have gone away once I have gone back to the stock cat.

Utah S2K

I'll let Honda know.......

Utah

ktwenty

Have the same issue as first mentioned seems like a common issue, honestly I'm lost as to the cause of this. Would like fins out a possible fix tooo.

cosmomiller

This thread reminds me of the effects commonly seen when Seafoam is used. Lots of thick white smoke coming out of the exhaust. It appears Seafoam is not the culprit here but the mechanism may be. Some kind of buildup is combusting. Buildup of oil, hydrocarbon deposits coming loose, all could bring this about.

Billman250

Utah did you have different results? Duration of drain, oil temp, and angle of car when draining can affect your outcome.

Slowcrash_101

This is exactly what happens, especially on AP1's that have a propensity for running rich, consuming oil, having a high emissions exhaust plus a lack of emissions control devices like the catalytic converter. A HFC may filter out NOx, MAAAYBE some CO gases but won't do squat for HC, which is the smelliest dankest crap your car puts out, and HC it will belch if you run anywhere below stoichiometric. Add in a PVC system that can and does allow oil vapors to condense in the intake manifold, and well, you can guess what can happen.

It won't do it with a working OEM cat because it's a 3 stage and it's designed to control Hydro Carbon HC emissions, as well as Nitrates of Oxide NOx, and somewhat control carbon monoxide CO.

zeroptzero

yup, mine was only noticeable when running a high flow cat, and no longer noticeable with my oem cat.