Sounds like you may have an exhaust leak. Do you have any other symptoms of a leak?

I had very little steam coming out of the exhaust myself.

For there to be steam coming out of the engine compartment wouldn't there have to be a leak somewhere? You are putting water directly into the engine. It should only be able to get out through the exhaust. Are you sure it wasn't smoke coming from underneath just exiting from the engine compartment?

did you accidently spill in the bay? gotta be a leak if not. a good way to test would be have a friend put the water on and you eyeball where the steam is. incase you didnt know, i will tell you. dont use your hand. steam burns are pretty bad.

I think you guys are right (regarding a leak somewhere). I replace the catalytic converter a couple of years back and didn't change the very rusty/corroded gasket between the DP and the cat. Probably leaking there and winds up looking like its coming from somewhere in the engine compartment...

I did this today and I didnt really notice any difference in driveability, but I did noticed the idle is smoother and more stable then before.

I found that tightening the idle adjuster screw directly above the throttle lever, made the job easier in that the idle would stay at a consistent 3K rpm during the cleaning.

That is a good point. If you use the screw you can keep an eye on other things like the cat, and also not need to worry a bout being burnt.

Do you run AI now, and how fresh is your engine?

The engine is a reman from the previous owner and the mileage is estimated 50-60XXX because my odometer is broken.

The engine is stock and I dont really have any mods besides for reliability. I did this to help clean up the carbon in the engine for better performance, longevity and help me pass smog. No alcohol injection, I wish I had something more exciting to say lol

What size tubing did you guys use? There are a few different diameters available at the store here

I used some left over hoses that were the same as the rats nest.

Thanks
I used 1/8" hose... it was tight but it worked

I had a good amount of steam come out... and I had 2 greasy/wet spots on the cement floor afterwards (one lined up with each exhaust tip)
Should be a good sign

Did mine today, one rotor at a time, had no problem keeping it at 3K with a long hose I just sat in the drivers seat. No steam but some water oil mix dribble under the car. Took about 3 minutes per rotor. Stock original motor 43K miles seems to run a bit better but it ran fine before...

The difference wasn't huge for me but it was free and worth it. I think it would be even better if there was a nipple just before the throttle body. That way it could clean out the junk that collects there too.

Just make sure you change your oil after. Mine looked awful.

Interesting, I think I'll give this a try

key is to keep the engine running as low in RPMs a possible but keep it from stalling out. if the RPMs are too high then the water evaporates too quickly to knock much of the carbon off the rotors.

The higher rpm you run, the less vacuum you will have therefore you will pull water in much slower. Keep it well under 3000 if you can. My car sucks virtually no water in the higher RPMs and the cat got orange.

Safe bet is to keep the revs low and have somebody watching your cat. I'd put a nice fan in front of your car blowing air under it.

isnt this procedure like subaru's upper engine cleaner ? anybody used those before ? subaru owners swear by them.

I'll keep the tips in mind. I'll give it a shot on monday

Having a mate watching over the progress is a damn good idea.

Pic below is the result of not having an observer (cannon muffler prob didn't help).

No, not my car!

Was this a result of the hot gases simply flowing up since the car isn't moving? Should a fan be placed towards the back somewhere to keep the gases away from the car?

that was caused by other issues, not the water treatment, running far too rich.

I've read that the ECU runs the engine very rich during this water ingestion process. I think it may have something to do with the cat getting red hot even though it's under no real load.

the engine is misfiring and is running rich because of that unburned fuel naturally during this process but that example above is an excessive example. more than likely that car was already tuned quite rich, was dumping water into both rotors at high RPMs and was igniting the fuel in the exhaust which was causing it to burn off after the tip.

it is pretty hard to miss balls of flame coming out of your car at a standstill and the smell of burning plastic.

as well, it is a good idea to only do about 16 ounces of water at a time and only do one rotor at a time. the exhaust will get quite hot after even that amount so letting it cool between each treatment is a good idea.

Based on what? Someone wasn't paying attention and it is an extreme example. I also suspect the car may not have had a cat. But what are these other "issues" and what makes you suspect it was running rich?

because the exhaust was obviously shooting flames out and/or glowing red hot all the way to the exhaust tip to cause that. in either case that is not something i have ever seen while doing the treatment the way many have described in this thread. the car was being pushed far too hard on the treatment or was running so rich that the exhaust was literally shooting fireballs out of the exhaust which is caused by running far too rich.

a cat will keep the exhaust from igniting post cat but it still isn't an issue, i and many do this treatment regularly and have full open exhaust without the exhaust superheating or shooting flames.

basically the car has to be running properly and the treatment not done so extensively that the whole exhaust system is glowing yellow. not saying that it still can't be done but you have to monitor things while doing the treatment and give the car a break periodically.

You assume too much. I see no evidence that there was ever flame coming out the back. I DO see evidence of radiant heat initially rising up behind the bumper cover. Hence the hole just above the exhaust tip. I see evidence of some initial melting and ultimately the plastic ignited from that radiant heat causing the visible soot. But not necessarily from "fireballs shooting out" of the end of the exhaust.
The car was just as likely running normally and well tuned as having any issues.
Gomez's point, and mine is... this too can happen to anyone with sufficient lack of attention, no cat and water ingestion that lasts WAY too long.