FlyYellow

So I passed my CA smog dyno test by the short hairs.

The test is conducted at 15mph and 25mph

For the 15mph test: Hydrocarbons max 50, average 13, measured: 46.

For the 25mph test: Hydrocarbons max 85, average 21, measured 64.

I was not pleased with how "dirty" my car runs and having a wife who is an avid environmental scientist (i hate to admit these #s to her) I feel like I should do something about it.

I've had a full tune-up about 3k miles ago, so i don't think it is spark plugs.
I've never changed the O2 sensor. But then the CEL isn't on and since there are no faults i keep thinking it is ok. Is it possible to have a lazy O2 sensor?

Could it be my cats are tired?

Could it be lots of carbon buildup?

Any thoughts?

Cheers,
Boris

chris walrod

Borris, was your car REALLY warmed up? Like thoroughly as warm as you can get it (legally)? The cat needs to be hot to work the best.

Too bad you cant get a smog check at the track. Pull off the track after your session is over, nice hot car...

24FPS

hey man! you passed!

superpat

Coincidentally, I had my CA smog done today too - these are my figures:

Idle 795 RPM Max 100 Ave 17 Meas 4
2409 RPM Max 130 Ave 12 Meas 6

My motor is completely stock - it's a C4, so they don't put it on the rollers. The guy did warm it through thoroughly though.

Sounds like you have problems somewhere along the line...

Cheers,

Pat

Glen

Boris, dont forget that I have a 12000mile 95 cat if You need it.

FlyYellow

The car was hot. I drove it ambitiously and quite a bit to get it nicely warmed up. It ran for a good 20mins at higher rpm to make sure it was nice and hot.

glen - thx for the offer. i guess i'm trying to figure out if it is the cat or carbon buildup, or lazy o2 sensor....

cheers,
boris

CP

Hey Superpat,

Coincidentally, I had my CA smog done today too - these are my figures:

15 mph: 2,361 RPM Max 85 Ave 21 Meas 12.
25 mph: 2,296 RPM Max 50 Ave 13 Meas 6.

I went from CT Automotive directly to the smog station. The RUF passed with flying colors. I have an appointment to register it soon.

CP

chris walrod

did you guys have a group buy on smog checks today?

I have got to get a smog in Feb. Dreading it as I always do...

What a sense of accomplishment passing smog, I know how good it feels to pass!!

kary993

I did the test twice due to the readiness codes not being set and here were both of my results. Much lower than yours Boris. It will be interesting to find out why. If you please let us know.

Test 1:
For the 15mph test: Hydrocarbons max 55, average 9, measured: 27.
For the 25mph test: Hydrocarbons max 39, average 7, measured 17.

Test 2:
For the 15mph test: Hydrocarbons max 55, average 9, measured: 26.
For the 25mph test: Hydrocarbons max 39, average 7, measured 15.

Note sure why you woul dbe having such high numbers.

superpat

lol! I just bought the car, so I had to get it smogged to change the title (is that the correct terminology???). I know Don Wise at CT reset some codes when he did the PPI - I think that may have helped me along a bit...



Pat

FlyYellow

i looked at my previous test 2 years ago and noticed that my hydrocarbons were also high at .96% (max is 1.0%).

this tells me the engine is running fat and that the likely culpirate is the 02 sensor. in my case i just have a single 02 sensor (i think since i have an obd I car). so i think i'll just order one and give it a try. it would be interesting to do a retest and see if it gets better, but i guess i'll find out in two years...

on a sidenote, any good source on o2 sensors? should i stay with a dealer sourced one, or is a bosch one good too?

cheers,
boris

superpat

Two years!?!?!? We need to know the outcome!!! How about a whipround for Boris' next smog test?



Pat

CP

I actually had a little scare.

I knew the 95 is an OBD1 car. However, when Don's mechanic hook it up, it shows an OBD2 computer with the OBD2 plug. I read somewhere the the smog test machine reads what the OBD reads as well, so I was worried that the smog station's computer might fail my test just because it is confused by the OBD1 vs OBD2 bit. Turns out there is no computer hook up at all.

My code readout says a RUF OBD2 ECU. I must have one of the few 95 cars with a OBD2 ECU. I'm seeing Viperbob this weekend, will ask him to hook up his handy-dandy lap top to verify this as well.

CP

Dave Crellin

A lazy O2 sensor will throw a CEL and error code I think.

FlyYellow

guys a friend of mine has a CO sniffer. I'll do a before and after and report back....

boris