Rear O2 sensor delete?

[anwieczo]

Ok, so I replaced my exhaust system and and removed my cats. Now my car is running rich and stinks like gas because of my rear O2 sensor... I am wondering if anyone knows where I can get an MIL eliminator for my rear O2 sensor or any other method I can do to fix this??
Thank you very much for your time!!

[eekay]

Generally, removing your cats is not a very wise idea. You'll find that you actually lose quite a bit of power and torque and you're going to get a lot of backfires due to burning so rich. You can potentially end up frying some things in your engine as well due to the richness of the exhaust and the lack of back pressure. I would /AT LEAST/ put one high-flow cat in there to avoid any major damage. Otherwise, there are ways around bad readings by the O2 sensor but the workaround won't actually "fix" anything. It'll simply keep your CEL from turning on.

[Huffer]

Going catless isn't going to hurt anything but the environment. You're mad if you think it will negatively affect the car UNLESS the car is relying on a downstream sensor to make air/fuel adjustments - which Subaru's don't.

However, you should look into putting your Rear O2 sensor back into the exhaust flow with a spacer to reduce the amount of exhaust flowing past it. The O2 spacer method works well, or you can try a "J" pipe extension off your catreplacement pipe to screw the O2 sensor into.

[eekay]

Hrm. That's strange. I've heard the exact opposite about my '99 LGTL using the upstream sensor to adjust flow. In fact, when my downstream sensor goes bad (And it used to /A LOT/) I would burn so incredibly rich that a cat would only last maybe 3 months. I've been through 4 cats and 3 downstream O2 sensors with my Subaru before I sucked it up and went back to a two cat system to avoid paying hundreds of dollars every 9 months or so. Of course, this was before my turbo setup. I now run a single high-flow cat system with no catted up pipe and it seems to run fine. Go figure.

[anwieczo]

Generally, removing your cats is not a very wise idea. You'll find that you actually lose quite a bit of power and torque and you're going to get a lot of backfires due to burning so rich. You can potentially end up frying some things in your engine as well due to the richness of the exhaust and the lack of back pressure. I would /AT LEAST/ put one high-flow cat in there to avoid any major damage. Otherwise, there are ways around bad readings by the O2 sensor but the workaround won't actually "fix" anything. It'll simply keep your CEL from turning on.

I have to disagree with you here. After removing my cats I have had noticeable power gains. I still have a res and muffler so it keeps the backfires down. The only thing that bothers me is the smell of fuel after I shut the car off... :smt028 I doubt an O2 sensor delete would fix that.

[hrdrifter]

i dont know about you guys, but i love the back fires :razz: i got a lot more power after gutting my cats

[ouch1011]

I wonder if perhaps Subaru changed their fuel control logic for the 99MY. I know there are a lot of newer vehicles that use readings from the downstream O2 sensor(s) to adjust the fuel mixture to a certain degree. Toyota and Dodge are two that come tom mind. I haven't heard of Subaru doing this but I am by no means a Subaru guru. I do know that on my 98, I recently install a set of headers that completely eliminated the cats, and noticed a decent boost in power. No problems with the car running rich. Honestly, if anything, I would expect the PCM to lean out the mixture if it was using the rear o2 to control the fuel mix and the cats were removed. But, I hate the way cars with no cats smell, so I'll be installing a HFC shortly.

[anwieczo]

Has anyone who removed there cats ever had a problem with dripping fuel? Every time I shut my car off and come back after a while I have been noticing a few drips of gasoline and it seems to be coming from my exhaust...

[eekay]

Which part of the exhaust does it seem to be coming from? I never noticed any dripping fuel, but if it is coming out all the way in the back, that could be a major problem. Obviously, any unburned fuel coming out of your exhaust is bad, but enough unburned fuel to not even burn inside is brutal.

[anwieczo]

Nope no fuel coming out the back thank god!! I actually found the problem. BOTH of my right side fuel injectors are leaking fuel pretty bad. I don't know how that could have happened? Do you guys think its most likely the O-ring seals? I don't think I need new injectors because they are obviously still injecting :smt017