O2 Sensors

[howslowcanyougo]

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.

[LightningGSX]

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.

[howslowcanyougo]

Originally posted by LightningGSX@Mar 27 2004, 01:32 PM
If you don't get a CEL, I would assume one or both of the o2 sensors are bad.

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

[LightningGSX]

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.

[Jacek]

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

[Enes]

so when is that o2 simulator be ready?

-E

[GS_Turbo91]

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

[NSANE]

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.

[Enes]

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

-E

[95tsi]

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.