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That is the 3 pages I got from the DMV when I failed, please help me with what I can do to fix this, I have the Oxygen sensor replaced, plugs, wires, dist. cap, dist. rotor, new cat, new exhaust. So I dont know what else it could be except EGR valve and Air pump. Help,
Thanks,
Dan

 

Never had to pass emissions so I cant be much help with diagnosing problems. The fact that it passed on NOx probably means that the EGR is still working.

As far as the AIR goes. My friend whos a mechanic says that the air helps quite a bit. Its important to note that there is actually an error in the calibration that prematurly shuts down the air pump when the motor is above around 2000-2500 rpm or so.

Ill say one thing, the emissions when the car is in lean cruise look pretty good. Id set teh car up to run lean, throw some alcohol in the tank and see if itll pass, but thats just me Probably the fact that you have a stick doesnt help, either. Some other things would be maybe a weak ignition. That would drive the HCs up if the mixture wasnt burning completly. Hopefully someone who knows emissions testing will have more insight.

 

Also, have you made any changes to the car like timing, FP, etc? I assume that its stock. Another thing is that maybe they where being too aggressive when they performed teh test, althoug from the graph it looks ok.

I took a car in to have it tested and they actually peeled out on the dyno with it. Luckily it didnt fail emissions.

 

Bone Stock

 

If you have a scantool that would help greatly. Youd at least be able to see if all the sensor readings make sense and everything appears to work. winaldl is good and costs very little to set up.

 

Where could I get one of these scantools?
Thanks,
Dan

 

see the new to tbi sticky at the top of the board. There are some links in there to winaldl

 

Hey Dan... I live right down the street from you... I've failed emissions a lot with my car. Put some iso-heat in there, mess with the timing a little bit, and throw a new cat on it, and if your burning oil make sure your plugs are clean....Works everytime for me...:lala:

 

That's kinda funny that your on here too, I' never would of thought you actually were on here lol, well I love your car. You should stop by some time when your flying down the block. So far I have done, plugs, wires, dist., dist. rotor, o2 sensor, new exhaust, new cat. But one of the bolts on the exhaust manifold where they connect to the Y pipe are snapped off, so I'm prolly gona have to get that fixed first, before I can even think of passing.
It sucks but when this is all over, here comes the 350, as soon as I can find one :lala:
Well if any one else has some ideas post please,
Thanks

 

Could 160* thermostat be doing this, because of the fuel not burning off completely or something like that. I read this in a few places on this board..

 

what i see from those readings is your running some what rich. yes, too cold of a t-stat can make the engine run rich. other things to check are, fuel pressure, TPS sensor, coolant temp sensor, air temp sensor, exhaust leaks, air injection system. if the air injection is putting air into the exhaust manifolds the O2 sensor will see this as a lean condition & richen up the mixture.
make sure it is going into closed loop.
once you get it leaned out, the NOx may then fail, a rich mixture cools combustion chamber temps, so check the EGR system out & be sure it is working right also.

 

Explain closed loop please, i've heard this before but not sure what it is.

 

Any One ?????

 

In so many words, closed loop is when the ecm begins using the O2 sensor and the PID algorithm (code that adjusts the fueling based on the O2) to ensure that the air fuel ratios swing around stoich. This is needed because when the computer can take readings from the O2 it then has a way of making corrections to the fueling if things are off a little bit.

In open loop the computer just gives the ammount of fuel for what it thinks the air fuel ratios should be. If things are off, the computer has no way of knowing about it or correcting for it since the O2 readings arnt being used, not to mention that the air fuel ratio may not be stoich since the desired AFR varies with temp and MAP.

 

The bird finally passed, with flying colors, let's see what i've put in this car so far...
1. Catalytic coverter (twice, first one was clogged since I bought it)
2. EGR Valve
3. Oxygen Sensor (Twice, first one was defective)
4. One TBI Injector
5. Full Exhaust
6. Air Intake Temp Sensor
7. 4 Months of temp plates at 8 dollars a piece
8. 5 Emission Test, 15 dollars a piece at the 4th and 5th test
9. A headache and wanting to wrap the car around anything in site just so I dont need to deal with it anymore.

And finally it passed, after all that crap replaced because a Emission diagnostic shop said all this crap was bad, which I beleive them because I know the guys who work there and they would not just have me replace everything for no reason, they wern't doing the replacement work so it wouldn't of helped them to much. If any one else needs to pass emissions, and you live in the Milwaukee, WI area send me a message and I'll give you their number. What it came down to is between two things, either the cat, because of it being clogged (brand new) still not sure if that's what caused it or not, or the Air Temp sensor. The sensor was reading 85 degrees, when the air was about 45.
But it passed so if any one has questions just drop me a message
Yay, I feel like a hundred bucks, or is that just because I spent so much trying to get this piece to pass??? Well the 350 buildup is back in the pic so if you have a 350 Short or long block that needs to be rebuilt or you want to get rid of for cheap let me know. I have a T5 tranny (91 Bird formula).
YAY :lala: :lala: :lala:

 

hmm i woulda guessed a bad tune up, when you see the HC off that far it's usually crappy tune up. Co is usually a mixture problem

when you get em both off.. usually it's a tune up problem that ended up wiping out the cat... but this car seems atypical of that.