Another Failed Califorina Smog Thread

Ok so I hate Cali smog. Just had to rant for a second. I've never had this much of a problem smog-ing any of my vehicles or this jeep before. these are my results from the first fail.


1989 Jeep Wagoneer Limited 4.0 inline 6

Hc(PPM) readings

Max GP Meas
Idle-580 120 270 355
2500 RPM-2657 180 330 97

CO(%) readings
Idle-580 1.00 2.50 .23
2500 RPM-2657 1.00 2.50 2.89

fixed misfire, did tune up, replaced catalytic converter and 02 sensor.replaced injectors still failed CO% and HC(PPM). Results from second fail.

co(%)
Test RPM MAX GP MEAS
IDLE 620 1.00 2.50 6.36

2500 RPM 2370 1.00 2.50 9.54

hc(ppm)
Test RPM MAX GP MEAS
IDLE 620 120 330 203

2500 RPM 2370 180 270 153


My CO% is 6 times the max limit at idle and over 9 times the max limit at 2300 why is this so high with a new cat, tune up, 02 sensor, injectors?

After worrying quite a bit about smog, today I got it checked and passed with incredibly good numbers:


15 MPH Test:

RPM: 1615
CO2 (%) Measured: 15.00
O2 (%) Measured: 0.01
HC (PPM) MAX: 54 Measured: 9
CO (%) MAX: 0.69 Measured: 0.01
NO (PPM) MAX: 527 Measured: 0

Result: PASS


25 MPH Test:

RPM: 1683
CO2 (%) Measured: 15.10
O2 (%) Measured: 0.00
HC (PPM) MAX: 38 Measured: 7
CO (%) MAX: 0.83 Measured: 0.01
NO (PPM) MAX: 780 Measured: 1

Result: PASS

When I got the Jeep a year and a half ago, there was a smog VIR in the glove box for the change of ownership. It passed, but only barely:


15 MPH Test:

RPM: 1585
CO2 (%) Measured: 14.30
O2 (%) Measured: 0.70
HC (PPM) MAX: 54 Measured: 47
CO (%) MAX: 0.69 Measured: 0.21
NO (PPM) MAX: 527 Measured: 516

Result: PASS


25 MPH Test:

RPM: 1572
CO2 (%) Measured: 14.50
O2 (%) Measured: 0.50
HC (PPM) MAX: 38 Measured: 29
CO (%) MAX: 0.83 Measured: 0.06
NO (PPM) MAX: 780 Measured: 108

Result: PASS

What did I do to get the numbers down so much? Pretty much everything. I was convinced that I would not pass again, and I was having Sudden Death syndrome, so I basically did a full ignition tune up and replaced the exhaust with a CA compliant OBDII catalytic converter.

It has new:

Coil
Plugs
Plug Wires
Cap
Rotor
Crank Position Sensor
MAP Sensor
IAC
All new vacuum lines
K&N Drop in filter
Downstream O2 Sensor

Plus, the cooling system is all new.

Also, right before the smog test, I got the oil changed.

I would have been very surprised if it HADN'T passed, but I was not expecting it to be THAT clean. My 4.0 passes the sniffer cleaner than my Corolla.

Admittedly, this is on a '96 Cherokee with Mopar Fuel Injection, OBDII, and Federal Emissions. Still, its running SUPER clean. I'm very happy with these results.

Not to be mean but u didn't help me. My jeep is a renix not obd2 also it's a low output motor and yours is a high out put motor. I changed my spark plugs, rotor cap, new magnaflow California CARB compliant catalytic converter, new 02 sensor. Changed injectors.

Did you replace the pcv, and check every vacuum line? Also, clean your throttle body, and either clean or replace the IAC. Did you check your TPS? Also, can you adjust your base timing on Renix? I don't kn0ow the answer to that, but I do know timing plays a role.

Also, does the new CAT have air injection?

I would be looking for a vacuum or exhaust leak that is causing a lean condition.

Pcv is fine its not clogged,New IAC, cleaned throttle body, New TPS and adjusted. New vacuum harness. On my first fail I was told I had a lean misfire. I replaced my injectors with the 703 ones out of neons and other 2.0-2.4 engines. Fixed my misfire but know in my second smog fail I'm running rich. So some where my fuel is not regulating and the engine is dumping more gas. Timing is none adjustable it's either right or wrong. Also checked fuel pressure and the needle on the gauge shakes around 32-34 psi. When I pull the vacuum off the regulator goes to 40 psi. When I accurate the pressure goes up maybe 1-2 psi the it drops below 32-34 psi. When I turn off the engine my fuel pressure goes to 40psi. I've let the gauge set from turning it off and in 24 hours I lost around 10 psi. Is that good or way to long to hold pressure?

Also could a faulty coolant temp sensor or manifold intake sensor cause my high CO%? Running rich

Check for a good seal on the exhaust where it connects to the cat. Also, engine temp is important. You should make sure you have an OEM rated t-stat. Yes, faulty manifold and temp sensors can cause the engine to run rich. The problem with Renix is that you can't plug a scanner in to see what the sensors are sending to the computer, so it becomes a lot of guesswork. However, Renix aside, the basics are still the basics. Your fuel pressure is fine, and the regulator looks like it's working.

One other thing to look at. Make sure the gap on your plugs is correct. When I changed my plugs, I found that the PO had gapped them at .070, which it twice the OEM gap. That causes problems.

Also, a weak spark from the coil module can cause the engine to not properly burn the fuel mixture. For smog, I'd go with OEM injectors. A lean misfire is cause by a vacuum leak, not the injectors.

Did you test your O2 signal? I found my older backup sensor was working better than a newer installed sensor.

Also, make sure your EGR valve is operating.

Search my posts, I had a recent thread regarding my smog fail issues, there was a lot of really helpful advice offered that resulted in my passing with flying colors and my XJ probably running the best it has in the 6 years I have owned it.

Pm Ecomike, he is pretty knowledgable about renix smog stuff

greenchevy said:

Also could a faulty coolant temp sensor or manifold intake sensor cause my high CO%? Running rich

Click to expand...

Yes, these sensors will affect the readings.

Move the hell away from cali.. Hippie state. Virginia would welcome your XJ with open arms

Just replaced spark plugs, new gasket before catalytic converter. Changed old injectors because they were not all the same also they had a lot of corrosion built up and i couldn't clean all of it because it moved in to the injector clip wiring. Also i could take off the number 2 injector plug and it didn't change the idle of the jeep any.

Boost Happy said:

Move the hell away from cali.. Hippie state. Virginia would welcome your XJ with open arms

Click to expand...

I like this suggestion the best. In one year your rig will be exempt in Texas, like next month!!!!

With that said, you have a lot of work ahead of you!!!

You need to get a good quality analog volt-ohm meter. And then read the O2 sensor data to get a better picture.

Start with some raw basics, like checking each and every Renix sensor ground for a good ground, and fix any that are too high, as in over 1 ohm. Search here for Crusier54 's guide to Renix ground refreshing, and other how to fixes! It well organized and great start.

Check the CTS, MAT (or also called an IAT), sensors at two temps, and MAP sensor at 2 operating conditions to verify they are good.

The EGR valve may be bad, stuck!!!! It can be easily tested, search for how to old threads, "Renix EGR"

Check the spark plugs for signs of a bad or weak or rich cylinder, black carbon, oil, or.....

Test the compression on each cylinder.

Do an aerosol spray (Carburetor cleaner, or propane fuel) to test for intake manifold or throttle body gasket leaks.

What if any Mods do you have, large tires, gearing???? Not relevant now for a gross problem, but may be later on...

Are the injectors new or used?

Is the any kind of miss at idle?

Have you checked the fuel pressure regulator vacuum nipple for signs of fuel? (as in a leak!!!!)

Boost Happy said:

Move the hell away from cali.. Hippie state. Virginia would welcome your XJ with open arms

Click to expand...

I am not going to start advocating CA smog laws, but based on the final numbers I got with my 25 year old original equipment jeep I gotta believe that if everything is operating correctly (which I think is what we want) this should be a reasonably passable test.

I also gotta believe that "finding a way" to pass may just be overlooking or avoiding a proper repair.

I might change my tune in 2 years when I have to retest.

And YES if you can get and follow Ecomikes advice, you are in good hands.

88trailcrawler said:

I am not going to start advocating CA smog laws, but based on the final numbers I got with my 25 year old original equipment jeep I gotta believe that if everything is operating correctly (which I think is what we want) this should be a reasonably passable test.

I also gotta believe that "finding a way" to pass may just be overlooking or avoiding a proper repair.

I might change my tune in 2 years when I have to retest.

And YES if you can get and follow Ecomikes advice, you are in good hands.

Click to expand...

I remember yours, it was a tough one, not a one bad item fix, LOL. But it followed logic and was fixable. When working right jeeps are great at passing smog tests.

So far I've disconnected all the pigtails I can see and spray them with contact cleaner. I've upgraded my braided wire strap with the napa one and I'm adding the battery ground to radiator support as well. My jeep has a 3 inch lift with 31 inch tires and stock gearing. How do i test the Manifold air temp sensor and coolant temp sensor(is this the sensor on the drivers side of the engine block?) Do i check them with the engine cold and then check them with the engine at normal 210 temp? Do i just unplug them or do i prob them while they are still plug together? Does the engine have to be running? Can i use a multimeter to test them? What am i testing for ohms? What resistance should i be looking for? I've tested the egr with the procedure from All Data and it functions and so does the diaphragm. The injectors are used but i have put 3m fuel system tune up kit in the engine and gas(bottle of engine combustion cleaner, throttle body cleaner, fuel injector cleaner). I can not feel a misfire when it is idling and when you accurate it doesn't backfire. I have taken the vacuum hose off the fuel pressure regulator and don't smell gas. Also i tested the regulator and it seems to be functioning.

How did you "Fix" the missfire?

greenchevy said:

Ok so I hate Cali smog. Just had to rant for a second. I've never had this much of a problem smog-ing any of my vehicles or this jeep before. these are my results from the first fail.


1989 Jeep Wagoneer Limited 4.0 inline 6

Hc(PPM) readings

Max GP Meas
Idle-580 120 270 355
2500 RPM-2657 180 330 97

CO(%) readings
Idle-580 1.00 2.50 .23
2500 RPM-2657 1.00 2.50 2.89

fixed misfire, did tune up, replaced catalytic converter and 02 sensor.replaced injectors still failed CO% and HC(PPM). Results from second fail.

co(%)
Test RPM MAX GP MEAS
IDLE 620 1.00 2.50 6.36

2500 RPM 2370 1.00 2.50 9.54

hc(ppm)
Test RPM MAX GP MEAS
IDLE 620 120 330 203

2500 RPM 2370 180 270 153


My CO% is 6 times the max limit at idle and over 9 times the max limit at 2300 why is this so high with a new cat, tune up, 02 sensor, injectors?

Click to expand...

Has it passed this smog test with the 31" tires before in the same smog test?

Used, non OEM style(?) fuel injectors could still be a problem are they 20 lb injectors?

greenchevy said:

So far I've disconnected all the pigtails I can see and spray them with contact cleaner. I've upgraded my braided wire strap with the napa one and I'm adding the battery ground to radiator support as well. My jeep has a 3 inch lift with 31 inch tires and stock gearing. How do i test the Manifold air temp sensor and coolant temp sensor(is this the sensor on the drivers side of the engine block?) Do i check them with the engine cold and then check them with the engine at normal 210 temp? Do i just unplug them or do i prob them while they are still plug together? Does the engine have to be running? Can i use a multimeter to test them? What am i testing for ohms? What resistance should i be looking for? I've tested the egr with the procedure from All Data and it functions and so does the diaphragm. The injectors are used but i have put 3m fuel system tune up kit in the engine and gas(bottle of engine combustion cleaner, throttle body cleaner, fuel injector cleaner). I can not feel a misfire when it is idling and when you accurate it doesn't backfire. I have taken the vacuum hose off the fuel pressure regulator and don't smell gas. Also i tested the regulator and it seems to be functioning.

Click to expand...

It had passed smog the two years prior with the 31s. I read that running the 703 injectors can cause the engine to run rich for a few days until the pcm adjusts don't know how much truth behind that though(http://www.jeepforum.com/forum/f11/injector-swap-writeup-4-0l-1224714/). But i haven't driven more then probably 30 miles with the injector swap. I had a terrible misfire. I checked the injectors and plugs and there was a lot of corrosion in the injector prongs and wire connectors. I read that corrosion in the injector plugs can cause voltage lose and a misfire. Also I had different injectors installed from the previous owner. They where 4 Tomco rotary disk injectors and 2 completely different injectors. So i figured since i had corroded injectors/ plugs and different injectors i would upgrade them and make them all the same. When i replaced the injectors with the neon(703) injectors my idle was smooth and my very noticeable misfire was gone from what i could see, hear, and feel when i put my hand on the valve cover. Also my tach on my dash doesn't drop like it did before with the injector swap. The injectors are supposed to be almost identical to the stock injectors (21.3lbs.). I read a few forums where people had passed cali smog with these injectors with no problems( http://www.naxja.org/forum/showthread.php?t=1086069).