O2 Sensor Gone Bad? - Honda Prelude Forum

Falude · 04-16-2008, 05:10 PM

Hello everyone, I have been having an ongoing problem with my Prelude for the past two years now, and I am turning to you guys for help.

I have a 1996 VTEC with 90k on it. Additionally the car has an AEM V2 intake and Greddy EVO2 catback on it. The car has always been well maintained, mobil-1 oil, etc.

Anyway, the problem is that the car blows out a fine particulate black soot all over the back of the car. You can clean the car and about a 100 miles later the back of the car is covered in a film of soot. The problem existed before the intake and exhaust were added, and the problem has been going on for a while. I have had the car into two Honda dealers and they haven't been able to give me an answer. They have both said that the air fuel curve on the car is just about spot on. The car doesn't burn any oil or seem to have any known mechanical problems.

Last year I replaced the EGR valve as that code came up, but that didn't help correct the problem.

I was wondering if maybe it could be an O2 sensor problem? At this point I really don't know, but I am up for any suggestions. On my 95 H23 I never had any problem remotely similar to this. Sorry for making this so long, but I am about at my wits end.

93H22ALude · 04-16-2008, 05:38 PM

If the dealership says the air/fuel curve is perfect then I dont think an O2 sensor would fix it because a bad O2 would make the ecu just run super rich which could be the cause of black smoke but if your curve is right then that shouldnt be the issue. Try replacing the cat(i know its expensive) but that could be why

lude4lifeh22 · 04-16-2008, 05:42 PM

h22's will do that. I get the same thing, as do many others.

Falude · 04-16-2008, 07:38 PM

So if this is a common occurrence on h22's then are you saying that there is nothing wrong with my prelude?

Is there anything that can be done to stop or correct this?

Thanks.

93H22ALude · 04-17-2008, 12:45 AM

I guess it could be called common but I dont have that issue. or... didnt till my O2 went bad but thats just recently. anyway your cat might clean it up a bit but idk how much

lude4lifeh22 · 04-17-2008, 01:32 AM

^^The catalytic converter could be not running as efficiently, but its still operating correctly if you arent getting any CEL's (96+ are OBDII if I remember correctly).

^The H22 Vtec does tend to run rich while vtec is engaged. If you dont vtec much, you most likely arent creating as much suit.

Unless your rear end is getting COATED in the black stuff, and I mean drenched in it, I wouldnt worry about it, especially if the dealer already stated that your air/fuel curve is ok.