Failed emissions today, way too high on CO

[foyburgher]

My 1983 944 failed the dang emissions test today. BADLY. Last year my numbers were way under the limits.

What do my numbers tell you? I'm going to replace the O2 sensor tomorrow. Please be it... Please be it...

My vehicle: HC 1.06 gpm CO 23.85 gpm NOx 0.98 gpm
Test Limit: HC 0.80 gpm CO 15.00 gpm NOx 2.00 gpm
So, my HC and CO are way over the limit, but my NOx is nicely under the limit.


Last year my CO was around 3. This year it's over 23. Would adjusting the idle have anything to do with this.

BTW, I've had the car for a year and you folks have been a huge help... So thanks for all the posts.

[SoCal Driver]

Depends on how you adjusted the idle. Seems to me that it's running a little rich. O2 sensor, AFS and engine temp sensor could be at fault. Running rich also whacks the converter.

What were your numbers from last year? Here in SoCal they test the cars every two years.

Problem is the states keep lowering the numbers and expect older cars to match numbers that are lower than the car produced new off of the show room floor.

[foyburgher]

It turned out to be the Oxygen sensor. I re-tested today, and my numbers were almost identical to last year's, and way below the limits.

Changing the sensor turned out to be pretty easy. It's incredible what you can remove with a flare nut wrench and a few careful taps with a 3 pound sledgehammer.

Thanks SoCal. I see you're keeping your 83 going too. Does your clock work? I'm going to leave mine broken, because one thing has to not work. Otherwise the Porsche gods get angry.

[SoCal Driver]

Clock works. Horn is tempermental because of the worn u-joint in the steering link. Odometer doesn't work. Fresh air blower selector switch has melted again. Takes a bit of twisting to get it to run on high. Need to replace the blower motor or just it's bearings. AC hasn't work since six months after I bought it. Heater works.

Just a few things.

[hpaulb]

Any sugestions on how to remove my 02 sensor. While rebuilding the engine, i had everything out but couldn't get that dam sensor of. Heated, large wrench and wacked it. no go. Now it's back in the car and plan on trying again but will have to do it installed?

[Razorback1980]

The only thing you missed with penetrating oil and an impact wrench. After that, I would use a longer wrench.

[foyburgher]

I used pentrating oil, heated up the exhaust pipe by driving the car around the block a few times, and also used a flare nut wrench. The flare nut wrench gives you good contact around all six surfaces of the sensor. I tapped the wrench with a small 3 pound sledgehammer and the o2 sensor came right out and the new one screwed in cleanly. Did you have any more luck getting your's out, hpaulb?

[hpaulb]

Havn't tried again. Probable will once it's in the garage for the winter. Just in case.
Might try to replace the mid pipe with the cat, with a straight pipe while I'm at it. Wunder if it will be to loud. I got the car with a chromed performance mufler of some kind and a fart pipe tip. Kinda loud now.

[Eldorado]

paul, your car is chipped is it not?
if the chip you have works like Wilks chip (i think yours is an AA chip..) then it ignores the signal from the o2 sensor anyway...