I passed! (but...)

[ScoobySteve]

So, I had the pleasure of doing one of our fun bi-annual smog tests here in the Golden State. I passed (original cat) but upon looking at the numbers it appears I've got something going wrong.

All of the test measurements produced numbers pretty far below the max and and below average...except for 1. On the hydrocarbon measurement at 15MPH I was exactly at the max and for the 25MPH I was close. I also noticed that my oxygen measurements for both of those were 0.0%. As much as I'd like to believe my engine is running perfectly efficient, consuming every oxygen molecule, I don't think that's right.

I'm thinking either my oxygen sensor is done or my AFM needs to be "retracked." Anybody with a BTDT story here?

[John_AZ]

Leave it alone if you passed and just smile as you go by an emissions station----until next time.

This may not help but the owner now lives in CA:
Failed CA smog... - Rennlist Discussion Forums

60K is usually max for a O2 sensor. Get the Bosch interchange that FRWilk posted. Follow his instructions-----crimp! No solder.
Oxygen Sensor

AFM
HondaDusTR did a complete video and writeup.
http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/493906-air-flow-meter-fix-refurb.html

GL
John

[ScoobySteve]

I don't want to sound like I'm complaining about passing, but it just seems like something might not be running right. I've also noticed that my motor seems to produce the most torque between 5000 and 6000 -- which isn't right.

I've never retracked my AFM as I'm a little apprehensive, but with 133,000 miles on the original one, it probably needs it.

[89-944NA]

scooby...if you ever have a problem with your smog again, I know a "great" smog guy.

[HondaDustR]

The FrWilk O2 part number worked ok, but a different part cross referenced by a Bosch guy on rennlist awhile ago seemed to work better for me and comes with a nice water resistant splice kit.

http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/514367-test-results-new-universal-o2-sensor.html

[ScoobySteve]

Originally Posted by HondaDustR

The FrWilk O2 part number worked ok, but a different part cross referenced by a Bosch guy on rennlist awhile ago seemed to work better for me and comes with a nice water resistant splice kit.

http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/514367-test-results-new-universal-o2-sensor.html

Wow...your results are interesting. My motor won't pull at all at 1500 smoothly in anything but 1st gear.

[HondaDustR]

Well, smoothly is a relative term here. It does kind of rattle the car, but the power pulses are nice and even and does make useable power, but it's also had a fresh valve job, mild porting work (especially intake), and a chip. The 944MAX chip does wonders for the low end part of the torque curve, but still uses the o2 sensor for part throttle, so the correct sensor did seem to improve it. It will pull in 1st, 2nd, 3rd, 4th that low to avoid a downshift around town. The stock chip would never do that. The 944MAX will definitely climb much bigger grades in 5th than the stock chip could.

[matthewb]

Originally Posted by ScoobySteve

I don't want to sound like I'm complaining about passing, but it just seems like something might not be running right. I've also noticed that my motor seems to produce the most torque between 5000 and 6000 -- which isn't right.

I've never retracked my AFM as I'm a little apprehensive, but with 133,000 miles on the original one, it probably needs it.

How do you know you are producing maximum torque in that range? Just by feel? At that point you are probably feeling the horsepower and your torque is already dropping off.

[ScoobySteve]

Originally Posted by matthewb

How do you know you are producing maximum torque in that range? Just by feel? At that point you are probably feeling the horsepower and your torque is already dropping off.

Easy...normally 944s fall off at high rpms. Mine doesn't. So either the engine is producing more torque up here than 944s (doubtful) or I'm missing some down low. I don't think horsepower can be felt, except in the emotive sense.

FWIW, I had an FRWilk chip in there but it was causing high-throttle detonation, even with 91 octane. It did, however, produce amazing throttle tip-in response.