ok, so a few months ago i was having the hardest time passing smog, i was putting out high (NO) counts because my egr wasnt opening enough, so i modified it to flow a little better and (NO) went from 1200 ppm to 450 ppm, max allowed is 772 ppm but when the (NO) dropped the (HC) went from 53 ppm to 108 pppm max allowed is 110, so i'm very close to failing on the (HC) side.

during the test my timing was at TDC and my adjustable fuel pressure regulator was almost maxed out for pressure, so maybe im running too rich from all the extra fuel and its causing high (HC)?


long story short i barely passed the last smog check. then the next day i was at the street races and was lucky enough to receive a citation from the CHP for no front plate/ moddified exhaust/ moddified emisions, so now i have to see a state referee and there going to do a smog check and measure the exhaust noise.

all smog equipment is in the car and functional, headers are CARB legal, the cat is a year old magnaflow highflow.

i'm also a little worried that i might fail the exhaust noise level check also, does anyone know about this, ill post on the exhaust board for help on that one


is there anything i can do to help.... would adjusting the fuel pressure to a much lower pressure help? is there any tricks i can do to help?

 

BUMP

 

Never tried this myself, but a couple guys back in my Honda days would retard the timing a bit and add some sort of fuel additive to help pass smog.

 

High HC is unburned fuel. I'd turn down the fuel pressure. You really should do the tuning via volt meter in the tech section to get your pressure right. https://www.thirdgen.org/o2tuning

 

You can't really tune with a volt meter. It much much more complicated than that. The proper way to tune is to datalog with free software we have available and a cheap 10$ cable.

Here's most likely what happened. When you increased fuel pressure the ECM tries to compensate up to around 10% (depends on which chip you have) once you max out the ECM's self tuning ability the mix will go rich and could possibly set a code. When we retune the ECM we try to get the fuel curves just right so that the ECM isn't compensating much at all. There are several parameters that are not effected by the ECM's self learning control, mainly pump shot, cold start, and WOT. Under these conditions the ECM goes back to your main fuel table, if this table no longer lines up with what the ECM thinks is happening, I.E. bigger injectors, more cubes, other modifications, then your fueling will be off.

What I'm getting at is that unless you are tuning your own chips leave the fuel pressure stock and be happy.

 

yeah hc are unburnt fuel too much fuel pressure would cause that.

 

another large reason for HC is burning oil. Older oil (near oil change time) burns off easier and will give you a higher reading.

Change it before you go and make sure your pcv valve is good.

If still high then it is possibly an over rich condition but this would also amount to high CO levels because if it is that rich (AFR > 14:1) the cat will barely function.

try it, see what happens

Brad

 

thanks for the input.... i've since turned down the fuel pressure, i played with it for a day and it only makes a difference if its maxed out or bottomed out, performance wise, i was thinking about the oil change to, right now 5 qts. of mobil1 full synthetic is only $20 at wallmart

pcv valve is good.... about 2 years old and all ignition system is within 1 1/2 years old


i need to replace my valve seals.... nothing says classy like a big-ole blue puff of smoke on start up

 

i just went through this but Arizona measures grams per mile. I changed plugs, cap and rotor, pcv valve, and changed the oil. MUCH better, however my car is modded more than yours... it took a wideband and lots of data logging and tuning to get it to pass the 4th time through. If you are pretty well stock besides exhaust. Put your fuel pressure back to stock for sure.. I think running lean and letting the egr take care of it and the computer compensate a bit for the fuel is going to help a lot. On my datalog of my emissions run, they never go 100% throttle. if they do in Cali thats BS in my opinion. Cali sucks for emissions... cant beleive they have referees!

 

First post in awhile. Trouble getting message boards to pop up. I agree with retarding the distributor. I did this with my father in laws truck and it was awful. It ran good normally but would put out a white cloud when starting that would make you close your window. It ran good and didn't smoke (visable) running down the road.

Retarded distributor and it barely ran. Stalled out 3 times trying to get up a 1" ledge in concrete getting in station. All the people said no way on passing. It passed and father in law bought me a twelve pack. I retarded it in parking lot just around the corner and went back afterwards and reset it.

Give it a try. The better they run it seems the worse echeck numbers you get. crazy.

 

Since the last post in this thread, before yours, is 3 years old...I'm pretty sure he got it taken care of by now, or has moved on.

Sometimes it helps to look at the dates of posts, before responding.