Failed again, at 15mph for High NOx of 1400 it was 1300 the first time, but passed the 25mph with 600 vs. 1200, so we are making progress.
EGR is working up to specs for vacuum and electrical signals. I cleaned the openings deep inside from the nice brown like deposits, but it was not clogged and the engine stalls when you apply vacuum.
New Bosch O2 sensor, the old sensor was white, so definitively lean as compared to the one pulled at the junkyard for practice as I was trying to find out how to pull the electrical connector.

15 mph 1700 rpm, 14.4% CO2, 0.5% O2, 63 ppm HC, 0.01% CO, 1500ppm NOx
25mph 2800 rpm 14.4% CO2, 0.3% O2, 64ppm HC, 0.17% CO, 600ppm NOx

So the CO is really the low value, the tech said that a new cat would not fix it as it is a lean condition, this tech was better than the previous one as he conditioned the cat before the test.

Yes, I changed the cap and rotor that were rusted, and put new spark plugs.

the carb fuel level is good, so the next step it to clean up the carb as there that supplemental electrically controlled needle to add gas. Unless it is the air cut off valve that is stuck open.... but it was regulated as specs.

Time to pay the $50 for the 2 month extension.

Thank you for reading

 

This post has been visited, so here is a little follow up

Failed again after the seafoam treatment, but I like this failed part as the numbers are a bit different and show a definite trend on the lean side, still low CO but low CO2 and high O2. Time to check the fuel pump output.

15 mph 1700 rpm, 10.9% CO2, 5.9% O2, 80 ppm HC, 0.01% CO, 1400ppm NOx
25mph 1900 rpm 10.5% CO2, 6.5% O2, 76 ppm HC, 0.01% CO, 1400ppm NOx

Failed for Nox on both speed, but when compared to the passing of the previous test, you notice the lower CO, there is not enough gas and too much air as the O2 should be below 1%

Looking at the value of 2 years ago, the state has lowered the NOx level from 1300 ppm to mid 800 ppm.

 

that is gay, and in San Fransisco. 25 years here and no more emissions inspection. And you should only have to pass the emissions standard at the time the car was sold.

Bosch O2's are terrible.
Nox is basically entirely controlled by the EGR and cat on old cars. I dunno what "conditioned the cat" is supposed to be, but you need to drive it down the freeway 20min, jack up, have someone hold the idle up, and check the cat with a raytek.

 

Thanks, so what are the choices in O2 sensors.

Conditioning the cat is to keep the idle at 2500rpm for 1 minute before the car is rolled on the test bay, to keep everything hot and toasty.

Yes, I drove on the freeway for 20 minutes and picked up a smog station off the freeway ramp.

I'll check the temp on the cat.... with at high idle.

 

if the temp out of the cat isn't higher than what is going in, it's dead. make sure you measure at similar pipe. their can be many varying thickness of pipe depending how much it has been messed with before.

if the O2 you have is the fat body bosch with the nipple looking tip + holes around the edge, I really wouldn't keep it. An oem denso or NGK is what you want.

holy ****, checked worldpac and list for denso is $208.. our cost.. $29.

 

Thanks,

Yes, I have the fat one with the nipple and slits. I checked on amazon and it is listed for $28 with shipping. I checked the worldpac site, but you need to download a package and my OS is not supported.

 

well that was jsut me checking, worldpac is a direct distributor for shops. If you can find an actual denso for cheap go for. If not I could hook you up with it.
the thing with those crappy universal boschs is they don't switch fast enough and therefore closed loop may not be as efficient as it could be.

 

bosch= junk... if used in an OEM application it's pretty good. Can't go wrong with OEM suppliers!

Some guys run some acetone in the fuel tank, supposedly it cleans up emissions, cleans up injectors and cylinders, and helps the fuel burn better. I can't say if it helps or not, I ran 3 oz/15 gallons and noticed no difference. After my experiments I found that I should have run more (1 oz/gallon). It might help you, no gurantees. They don't do inspections here in the mitten state.

 

ya that is way too little. if you get desperate, get down to an 1/8 a tank of gas then put in a few bottles of rubbing alcohol. it will improve one gas, but raise another. been a long time and I can't remember specifics anymore.

 

Thanks for the fuel substitutes ideas.

I checked the O2 sensor voltage output at 0.5Volt, going up to 0.9 on acceleration and down to 0.1 when closing the throttle.... which seems about to specs.

I checked some of the sensor... and a mile of vacuum hoses..... the anti-afternburner valve have fail the test.... so it may be giving more air than needed.

Tomorrow will do the egr check valves.... just following the TSM.

 

Bring the pop corn.

A bit tired of monkeying around, I dropped the civic at the local gold shield smog check for the $90 diagnostic.

They called later saying that the EGR is not getting vacuum, I replied that I drove a whole day with a vacuum gauge T'ed to the vacuum line and I saw vacuum, it is low but within specs. The tech called back saying that in fact is gauge was not working, I hope that the gas analyser is working...... to my advantage.

As for the lower value above for the CO2 and high O2 value, the tech has found a crack in the tailpipe... so we have an explanation.... but it means that the NO was even higher......

For the next step the tech will cook the cat to clean it up by creating a misfire when unplugging a spark plug for a minute or two .... and then running the dyno when the cat is hot.... and hopefully to make it pass the smog test.

 

I don't know those civics for sure, but I do know 90-93 accords and the EGR is only supposed to see 8" of vacuum.

Raw fuel into a cat = dead cat. artificially heating a cat by setting it on fire is not the same as the heat created by the chemical reaction.

 

My EGR is up to specs, about 6" of vacuum.

It failed again after the cooking, but the Nox numbers are getting closer, but still too lean.

I need to explore the magic box.... the one with all the valves. This carb is more like EAI... electronic air injection, may be a valve(s) is not up to specs.

I scanned the schematics of the vacuum lines and color coded them for easy analysis.

 

I was denied an extension, so I had to put a new cat $300 and $100 for labor -this is the intake manifold attached cat- which was a real pain for the muffler guy, as the cat was poorly specs and barely fit.

Off for a nice drive, back to the smog test and failed with even higher NOx, the HC and CO are lower, but the NOx is in the 1600.

 

Today I had an appointment w the smog referee... he looked at all my papers, dismissed some... as I needed to have all the repairs justified with an invoice from a real smog station.... but as I have over $450 in bills.... I got a waiver.... for 2 years... so until December 2012, no need to rush.

 

I have found "1" intake leak, while putting a new alternator I noticed an intake manifold hose that did not look too good, there was some oil at the connector. The car being on blocks, I could spray some brake cleaner on the backside of the intake manifold while the engine was running and for sure... the idle went up. The catch is that this short hose is impossible to remove unless you pull half of the emission hoses around it if you can grab them.... so I slipped a clamp around it.... and no more wild idle after I sprayed the brake cleaner. Now the idle is up by 100 to 150 rpm.... The engine sounds better.

Did I fix it?.... probably..... The power is substantially better..... merging on one of those short uphill ramps, I was at the speed limit in no time....

 

Needing new tires soon, I decided to go for a smog test as it is due in 80 days, and it passed.

As you can see I lowered the timing to the maximum allowed, it is now 3 degrees lower than the specs of 20, it used to be 2 degrees, albeit I set it to 2 degrees lower than specs.

The NOx is below the max, but still above the average



Still lean, but it passed. The last highway ride gave me 43mpg. I used the lambda calculator to get 1.014 and a A/F ratio of 14.91

I have not solved the other issues with the cold foggy mornings... it has been sunny lately.