1G Failed smog check. high CO at 2500 rpms

[DROOPY209]

I took my car to get a smog check today. It failed. Here are the results:

_______________________________________HC _____________CO% ____________result
test _____rpms______|CO2%|___|O2%|____|MAX| |meas|____|MAX| |meas|
idle______|958|______15.1 |____|0.2|______|120| |43|______1.00| |0.01|______PASS
2500rpm |2630|_____|13.0 |_____|0.2|______|140| |119|_____1.00| |3.40|_____GROSS POLLUTER

I think it's the O2 sensor. It's still the original one and part of it is looks kinda broken.

It passed the test at idle pretty well, but once the rpms came on, the CO2% went down, and the Carbon Monoxide (CO) went way up.

You guys have any suggestions for lowering the CO down?

 

[Raph]

-if the CO is too high , then your Catalytic converter isnt working..

i-f your AFR/Lambda were out of whack,then youy o2 sensor is busted/exhaust leak.

so, get a new cat . (you def look like you need one..get a magnaflow ..there cheap and smog legal)

if your car barely missed the correct CO values,then your Cat wasnt warm enough..bring the car when its really warmed up... did the smog guy warm your car (like 2500 for 180 secs before testing??,if not rev her for 3 minutes outside before you begin)

 

[DROOPY209]

the CO passed at idle. It passed really good. Once the rpms came on, the CO2 went down to 13 which means really rich, and the CO went sky high.

Are you sure it's not more then likely the o2 snsor? I've never replaced mine, and i've had that car for over 4 years.

 

[Raph]

the CO passed at idle. It passed really good. Once the rpms came on, the CO2 went down to 13 which means really rich, and the CO went sky high.

Are you sure it's not more then likely the o2 snsor? I've never replaced mine, and i've had that car for over 4 years.

you mean the AFR went down to 13 .... (lambad < 0.97)

if the co reads more than 0.200 then you cat isnt warmed up..it should fall below that lvel

if your co stayed over something crazy like 2.000 then your cat is definatley furbared.

why dont you recheck the values on the printout you got.

and post em.

the only values which are important are CO %vol. and the Lambda/AFR values .

do you have a cell?your o2 sensor should throw a cell or at least measure it with a voltmeter at idle(shold bounce between 0.250 and 0.975 Volts )

 

[DROOPY209]

Ok....i changed the o2 sensor. Right before I changed it, I warmed up the car, drove it around pretty hard for a while and checked my logger. The old o2 sensor was having a tough time jumping around. Sometimes, it would stay in one place, really rich for a bit, then it would go to like .40, then ocassionally .60

To say the least, the old o2 sensor was being kinda "lazy"

I changed the o2 sensor with an OEM replacement from Bosch. I warmed up the car, drove it around for a while to fully warm up the cat, and then checked my logger. The new sensor was a lot more responsive, it was moving A LOT more, and at 2500 rpms, it was jumping all over the place, as opposed to the old o2 sensor which would kinda stay rich for a while at 2500 rpms, just sitting there, then moving really slowly, then kinda sit there.

By just changing the o2 sensor, the o2 on my logger is being A LOT more responsive, big time.
also, according to my logger with MMCD,
my tps at idle kinda fluctuates though, it jumps between 12 and 14%
My timing at idle is kinda jumpy too, it jumps around 10 and 13 degrees.

 

[Raph]

well try the inspection again(is it costly?).. but drive it really warm before hand.but i still see a new cat coming your way.

i cant believe you get to run a 1.00 CO at 2500.. here its 0.3 on older cars,0.2 on anything after 1996 and it has to stay at that value or less for 30 secs.

idle is 0.5 CO on older cars and 0.3 on newer cars.

 

[fittyonefitty73]

I would lean towards getting a new cat. High CO usually means you are running rich, but your HC numbers and o2 numbers could be lower, which leads me to suspect your cat is on it's way out. are you still on stock fuel delivery?

 

[DROOPY209]

smog tech accidently messed up the last test....he put in the computer that my car was a 1.8 liter N/A engine, going by a sticker that the hood now has on the car.

The car is actually a 92 2.0 turbo, AWD.