does anyone know if a resistor and a capacitor in series with the second 02 sensor voltage output wire make the check engine light for catalystic inefficiency go away?

 

Not sure but let me know how it goes if you figure something out.

Thanks

 

I'll practically guarantee that running a working cat will make your catalyst inefficiency CEL code go away.

First, you'd need to know what your O2 sensor is reading. Then you'd need to know what the ECU is looking for from that O2 sensor. Only then can you try to figure out a way to make the signal you have into the signal it wants.

FWIW, my rear O2 sensor fluctuates between .117v and 2.61v, while the front goes from .0195v up to .975v. If the voltage is too high, you'll get a CEL. Too low, same thing. The ECU also compares how often each sensor switches from reading rich to lean, and calculates a ratio that it checks to see if it should trip the CEL.

Looking at my log files, you'll have a hard time duplicating the behavior of the rear sensor, but you might get lucky and get close enough to make the ECU happy.

 

weird because my friend and I drove around with a scan tool hooked up and didn't see more than 1 full volt of it. The service manual says it should read between .6-1v when the engine is revving. mysz, A. do you have a stock cat, B. do you have access to a scope and if so a way to post a wave pattern.

 

I have the stock cat and a scope. Also a datalogger (which is what I'm getting my readings from). I'll see what I can do for waveform.

 

running catless on public roads=pointless stupidity




my .02

 

now that I think about it running catless on public streets is just as illegal as street racing, why don't we police discussions on purposefully defeating obdii systems to break emissions laws?

 

A good point, but breaking emissions laws is FAR less dangerous than street racing.

Other than both being illegal, there is no point in comparing the two.

 

Don't use a resistance buy a O2 simulator please it's a lot easier

 

my .02 manmade global warming is BS and so are alot of our emmission laws. If diesel pickups can mod their trucks and belch massive black smoke. I see no problem running catless other than legallity. Most new cars run so clean that even removing the cat will result in better emission than most older cars and definately alot less than any diesel pickup yet they get a pass?

 

I'm actually just curious if a resistor and capacitor will turn off CEL thats all. It would be so easy to solder one in series at either the ECU pin or under passenger seat (which is where connector for 2nd o2 sensor is). Besides if that does it why buy a 70 o2 simulater. In theory this should work. All the cat does is use up any remaining oxygen in exhaust pipe, The only gas the oxygen sensor can detect is oxygen. Which running no cat will create too much voltage since the o2 is used to generate a small voltage, but a resistor should create a voltage drop "simulating" a cat.

 

oh and I'm not sure if the computer would recognize excessive exhaust pulses that normally the cat would smooth out. Hence a capacitor to smooth out voltage signal. I just dunno what size resistor or capacitor to try

 

this is what you need http://cgi.ebay.com/ebaymotors/O2-Si...12392218QQrdZ1

 

rotfl! That's an anti-fouler. It should be <$2 at Napa.

edit: and yes, that's what I have on mine. %100 guarantee is crap because the spacing required varies depending on both your car and your set-up.

 

This is what you need http://cgi.ebay.com/ebaymotors/Dual-...06667970QQrdZ1