Cant pass CA smog!!!

[macatoni]

My CO is at like 4% when fuel preassure is at normal 40psi. If i back it down to where the engine bearly runs i can get it to the acceptable 0.7 but then my HC goes up to 1500 and my nox goes up to 2000!!! What can i do to get this thing to pass tail pipe emmisions? Any ideas appreciated...

[macatoni]

My 02 count driving is at 400 but sometimes jumps down to 003! My BL is 128 most of them time but jumps to 148 under certain throttle conditions. Everything else seems ok, tps .44, IAC 40, coolant temp 170, ats 130 during the test, INT 128. Im using a turbotweak chip but im not sure on the timing, i used to have an emmisions chip but i cant find it for the life of me.

Also the car is stumbling/misfiring at slight throttle. Any aggression with the throttle is disapears but when u first give it gas off the line or cruising with very little throttle is stumbles...

[TurboDave]

You need to leave your fuel pressure where it belongs and get yourself a smog chip, you'll need a good smog (emissions) chip and a good cat, and working EGR to get through the KA smog checks these days.
(my bonfidies.... I live in Southern Ka for over 10 years).

[STAGE 2]

Listen to Dave, hes the cali smog guru (and he don't even live here anymore). I'd give Turbotweak a call and pick up his emissions chip.

[blackstallion]

Make sure your plugs and wires are in good running condition first step,make sure your egr valve is working make sure that it stumbles when you manualy press on the backside of the egr valve or when you apply vacuum to it then hook up a scantool make sure the solenoid that gives it vacuum works.Check for vacuum leaks add some 100 octane 5 gallons then go.Oh yeah the chip I have in it is the throwback pitbull chip 26 degrees timing.I have the 237 regulator on it.

[BlackBandit]

Get a hotter thermostat, fix your misfire.

[SouthernCal GN]

Also, change your oil before you go to test- get that old nasty, fuel laden stuff outta there....

[turbo39151]

Check your tps and IAC for a fix to the stumble. Then look at coil pack and ignition module if you're having misfire. (maybe wires and plugs too)

I usually swap the cat, new O2 sensor, oil and oil filter change, a little alky in the tank and a can of "restore" in the oil... (this trick took my gross polluter truck to levels cleaner than my newer cars.)

BTW, I used the smog chip and it didn't seem to make too much of a difference (for me at least).

[macatoni]

I borrowed a set of 33lb injectors from Joe and a stock chip. Now i can pass everything but NOX which is up in the 1500ppm range. I checked my egr and when i depress the plunger the car does not change idle condition. I know that there isnt a block off and last time i checked it worked. My tps is .42 with smooth increase with throttle. my IAC is 40 at idle. I think i need an egr and maybe some new plugs, wires, and coil pack.....


So frusterating!!!

[blackstallion]

Your intake may have too much carbon if you depress on the plunger of the egr valve and idle does not change the diaphram is busted or there is carbon blocking the passages remove the egr valve and apply a vacuum gauge apply at least 10-15 inches of vacuum it should hold the vacuum if it doesn't at all you need a new egr valve if it does then its fine and you need to run some brake clean or carbon cleaner and use an old steel hanger to unplug the carbon blocking the egr passages hope this helps.Also if your egr has that much carbon your intake/throttle body,intake valves and top of pistons will also have tons of carbon which will increase nox more heat and too much carbon on top of pistons can actually artificially increase compression ratio.Run some sea foam directly into the intake.Make sure your cat is working,if you have a test pipe or cutout put the probe in it and see your readings if they are the same or a little different you need a new cat hope this helps.

[Drip Pan]

Emissions chips aren't required to pass CA, a well-tuned car is, along with a good cat. I use a regular higher timing chip for my 10-sec GN which has 72# injectors and 212/212 cam, and it passes fine with the fuel pressure set at 42 psi. I also have the capability of turning the dual fans completely off from the driver's seat, so I get car the good 'n hot (about 215*), then roll the car onto the smog dyno. I had to smog the GN just two weeks ago for registration purposes and the engine temp was in the low 190's about halfway through the test.

[Mac in SD]

Originally Posted by macatoni

I borrowed a set of 33lb injectors from Joe and a stock chip. Now i can pass everything but NOX which is up in the 1500ppm range. I checked my egr and when i depress the plunger the car does not change idle condition. I know that there isnt a block off and last time i checked it worked. My tps is .42 with smooth increase with throttle. my IAC is 40 at idle. I think i need an egr and maybe some new plugs, wires, and coil pack.....


So frusterating!!!

Put 2 bottles of HEET in a 1/2 tank of gas and try again.

[macatoni]

So u put on a set of known good injectors that got me running lean instead of rich. I put on a new cat and i took off my RJC powerplate to free u up the egr. Now i pass the 25mph test but not the 15mph. On the 15mph my Nox is up in the 2000 range!!!

Now what?

My scanmaster also crapped out on me. All the connections look physically sound however once the car starts it only displays several dots in a line on the bottom of the display.

[SouthernCal GN]

Do you have an emissions chip to your injectors, or a cat?

If not, get those items (as previously mentioned) and you'll be set.

[macatoni]

new cat and correct chip....

[SouthernCal GN]

Did you make sure your sensors are set correctly? My combo is more aggressive than yours, and I passed with a TT emissions, chip, turning the FP down, and turning the alky off.

Have you checked for vac leaks?

[Ed Valvo]

Exhaust leaks? Have you ever changed or fixed the infamous cracked drivers side header?

[macatoni]

Actually i just had to weld up the passenger side header at the turbo flange. I need to get my scanmaster working but i am 99.9% sure my tps and iac are correct cause i checked em two weeks ago and havent touched any of it since...

[blackstallion]

are you sure your egr valve is getting vacuum at the rite times hook up a scanner and see if the egr goes into duty cycle by 15 mph make sure the egr passages are not blocked if depress on the plunger and the idle does not change the passages are block or the egr valve is busted .did you apply vacuum to the egr valve the plunger should move freely and hold some vacuum if it doesn't the replace egr valve if it does the passages are blocked.Pour 5 gallons of 100 octane thats what my car runs on most of the time my nox are around 280 at the 15mph my car.Thats with a race chip 160 thermostat aluminum radiator (91 iroc 5.7)stock fan remeber nox is all about heat.

[QWIKWE4]

If you get a new cat get one for a late 80's or early 90's IROC Z28. Its helps lower the Nox. Its a 3 chamber instead of a 2 chamber. We put one on a friends car with champion heads with no egr ports and it passed CA smog easily.