fltechpilot

Hi guys, I just moved out to california from ct and you know what that means...smog testing!

Took the car today and failed for high NOx at 25mph; it was also close to the limit at 15mph. Everything else was very clean. Looks like the car is running too lean. Im thinking maybe the o2 sensor should be tested and possibly replaced.

I'm going to post the official results to see what you guys think. Any tips would be greatly appreciated!

Btw- the car is an 84 auto. New timing belt, water pump, Bosch copper plugs, plug wires, thermostat, all new fluids, all new filters including fuel, new fuel lines, tranny service, and probably more stuff that I'm forgetting. Just about to hit 91,000 miles and as far as I know it's the original o2 sensor.

Mongo

O2 sensor failures can cause these cars to lean out. Definitely look into replacing the O2 sensor and try it again.

fltechpilot

I also ran the car for a long drive before getting it tested and it sat for awhile heating up at the testing center before getting tested. Water temp was close to the second white line. Would I be better off getting it tested cold with these numbers?

rnixon

This thread has some good info / links for high NOx and testing the O2 sensor.

Jerry Feather

I am surprised. I thought when you moved to CA you can smoke just about anything and no one will even notice.

James Bailey

No Jerry that is a Colorado law !!

fltechpilot

R Nixon - I read that thread but was thinking there would probably be some differences due to my car being older. No MAF and all.

And apparently not Jerry!

Jerry Feather

Oh! I wonder how I would know anything about that.

Randy V

Have you tried a search? There are many threads here about your exact problem with successful solutions.

Mongo

Try the O2 sensor first. If you still have high nox you can open the black cover on the AFM and make some adjustments on the dial in there.

I know that adjusting the dial is frowned upon, but it can be the easiest way to get an L Jet car to pass by adjusting the spring tension on the barn door. You must remember how to set it back of course and count how many teeth adjusted clockwise or counter.

fltechpilot

I hardly post on here because 98% of my questions have been covered in previous threads and I'm not smart enough on these cars (yet) to really help anyone else out.

I understand the meaning behind high NOx, but I was thinking that by posting my specific results someone might see a correlation between some of my numbers that could point to a specific issue.

GregBBRD

See post #10.

The CO numbers from your test are not zero....which is the "normal" when the O2 sensor goes bad, but it is worth a try.

After that, you either need to make it richer or replace the catalytic convertor.

A new Factory cat would allow this car to pass without any other effort required. Forget the crappy replacement cats that the local muffler shops will try to sell you. Those things will clean it up, this year and maybe next, but certainly not the third year. And they will kill the performance. 928 International has a few of the factory cats, brand new, for pennies on the dollar of what they cost new, from the dealer.

I'd buy one of those and not worry about passing smog for the next 20 years.....

Chalkboss

I just passed Cali smog an hour ago, happy! It actually is cleaner (lower NOx and HC) than a year and a half ago when it was done. 87K miles on the car. Stock everything. I had fixed some vacuum leaks and it has a new 02 sensor since the last smog.
My CO is low (0.02) so Greg I guess that means the 02 sensor is working? Not zero but close!
I agree with the above, good MAF, sensor, and most of all good factory cats are needed to comply with California smog *****.

karl ruiter

Should clean up nicely and pass easily when you get it right. My smog guy used to run my '82 and say "new cars aren't this clean".

x98boardwell

Just went through this. Test O2 to make sure it is cycling. if not, could be bad cats. Cycling O2 is easy to do. Check my username and you will see what I just went through. Best of luck and welcome to CA!