Ok, so if i remove my cat, the rear 02 sensor is going to burn out?

and it is going to give me SES light. correct?

-E

On a 2g yes, it will.

It won't burn out, but it will throw a CEL.

Good addition. Thanks.

I think there is a kit you can buy to bypass that CEL for the second O2 sensor though isn't there?

CRAIG

Who cares :0 Car will run the same, just pull the bulb out!

DSMLink or an O2 simulator

Some resistors or a IC voltage regulator will do the trick.

how much?

-E

Every car is different when it comes to CEL codes. I know someone on here who vents their bov and was driving around a while with the MAS unplugged without the CEL poping. It was a 2g. With the MAS plugged in it still doesn't go off with the bov. My car (2g) pops a CEL when just venting a bov. With my MAS unplugged the car will not rev past 2000 rpm.

I still have yet to throw a single O2 CeL, like getto says, "It depends on the car". Do the "cat reduction" and see what happens, but I don't think it's a big deal.

If you don't get a CEL, I would assume one or both of the o2 sensors are bad.Or I have read about pre-2000 Mitsubishi's having a problem with monitoring catalyst efficiency, more specifically the catalyst test hardly ever runs.

That's interesting, I'm getting alot of 0 volt readings on my front o2 in my DSMLINK logs?

Not always, just sometimes, but I guess it should never read zero volts. so it maybe bad?

Anyway so if the front one goes bad, can it affect the back ones operation?

TIA.....

Howie

If its an intermitent 0 volts, your o2 sensor is more than likely at fault.Or I guess the o2 sensor wiring is a possibility also.Due to the fragile and easily contaminated nature of o2 sensors the don't really have a long lifespan.


A missing or faulty rear o2 sensor may have effects other than the CEL.I can't say this is fact, but it seems to me, if an OBDII ecu see's a decrease in catalyst efficiency(faulty or missing rear o2 sensor), it may alter a/f ratios to try and bring the catalyst efficiency back up.Proper way to get rid of it, would be to note average rear o2 voltage(should be 0.6-1.0 volts) before you remove the cat.Then put a high wattage resistor(12 ohms IIRC) across the heater circuit, and another resistor(to drop voltage to previously noted voltage) between the b+ heater wire and the o2 signal wire.

is there such a thing as having to break in an o2? mine was flatlining when cruising but now is starting to work..

so when is that o2 simulator be ready?

-E

2 of my buddies put in test pipes, one on an EVO and the other on a WRX. they put the O2 sensors back in, but with 1 or 2 washers on it to pull it out a little so it wont pop the CEL. both have had it like that for months now with no problem. just my 2 cents

I have had 2 2nd gen cars both with no cats neither one posted a cel not to say yours wont but once you get the dsm link you can turn off the cel for the rear o2.
Both my cars were 95s which is a bastard year not truely obd1 or obd2 but inbetween. That might have something to do with why it dosent through a cel.

yeah ONCE i get dsmlinkidylink... which is coming when btw?

-E

I have dsmlink with both O2 sensors and no cat. I've been running that for over a year with no cel's. I've had no problems with it at all.