I just had my car tested today and it didn't pass. I always keep up with all maintence and what not so I know it isn't running bad. Here is what I have done to the car,
-plugs, cap/rotor, wires, O2 sensor all within 10 months
-15psi guru chip set with 3 bar fuel reg.
-NEW 38mm Tial wastegate

I JUST had my car in the shop two days ago for the wastegate and they didn't notice ANY vacuum leaks at all. Here are my readings,

Reading ----- LIMIT
HC 127.1 ----- 168.0 ----- Pass
CO .66 ----- 1.08 ----- Pass
NO 2377.8 ----- 1208.0 ----- FAILED
CO2 14.51 ----- N/A ----- N/A

That just seems like a VERY high reading as well. I HEARD from some people it could be caused my running lean but my air/fuel is fine. I did have a problem with the stupid testing people because they put the car on spinners?? and drive it up to 25mph and hold it, well they were in 3rd gear!! That takes the rpm's down to about 1,800 or so. Would that cause some of it to? I drove the car for like 30 mins before and had about 1/3 of a tank of gas. I REALLY need to find out what is wrong. Anyone that has had the same results, what did you do? What is the NO so high??

 

High Oxides of Nitrite, are usually a result of low combustion temps. Spark plugs OK? Coil, distributor cap and rotor OK? Wires good? If all those are good, check a little sensor call the DME temp sender. It is on the drivers side of the engine just above the upper balance shaft. It has a blue pigtail lead. It's job in life is to tell the DME what the temperature of the engine (coolant) is so that the DME can adjust the spark timing to either warm or cool the engine. It is an open or closed type switch. Or it could be the cataylitic converter its self.

 

I have noticed that my temp sensor in my car has been pegging out at max temp. Would that be the sensor? I think I am going to pull the plugs and clean then well too. Would running the stock chips for the test help at all?

 

No, they are two different sensors, the one that controls the temp guage on the dash is on the radiator, left side about 1/2 way down. Stock chips couldn't hurt. How old is the O2 sensor?

 

O2 is about 6 months old. I think I might try the stock chips and clean my plugs. Would running the car hard before hand be good or not?

 

A lot of "bum dope" in this thread.

First off, the DME Temp Sensor II is the sensor with the BLUE connector near #1 intake runner. The device is NOT a switch. The device is an NTC or Negative Temperature Coefficient device, which means the internal resistance of the device is inversely proportional to its temperature. In other words, the resistance goes down as temperature goes up.

Second, the sensor in the passenger side radiator tank controls the cooling fans. For early cars ('83 to '85.0) the radiator temperature switch is a single pole, single throw switch: Fans are either on or off. Later cars use a two stage switch. At the first setting both fans run at slow speed, at the second setting both fans run at high speed.

Third, ALL of your readings are too high. My 951 tested with 99 ppm HC, 0.46% CO, and 14.4% CO2.

Fourth, your engine is running RICH, not lean!

Fifth, high NoX is a result of HIGH combustion temperatures and pressures.

Here is a link to an EPA document in Adobe . PDF format: http://www.epa.gov/otaq/consumer/05-autos.pdf

 

So how do I fix this then? Put the stock chips in for the test or what? How do I check that sensor for the temp? Can I clean it or does it need replaced??

 

My 951 is running with a 3.0 BAR FPR, Guru chips, and a ReliaBoost MBC, but without knowing what chips you have, I can't blame the chips. I have heard that AutoThority chips are less than desireable, but I have no first hand knowledge.


You can test the temp sensor with a digital ohm meter. At temperatures between 59 and 86 degrees F, the sensor should read between 1.45K and 3.3 K Ohms. An easy way to test the sensor is to remove it (You may lose some coolant), connect the meter, and then put the sensor in a pot of boiling water. As the sensor heats up the resistance should change.

Another test you can do with a DVM is "back-probing" the O2 sensor. Connect the negative lead to a good ground, positive lead to the sensor wire, set the meter to read the 2 volt DC scale, and start the engine.

As the engine comes up to temperature the meter should begin to inciate somewhere between 0 and 1.0 volts, with a typical reading at idle varying across 0.50 volts DC. If the sensor pegs high or low, replace it.

There are any number of things that can cause high emissions like high fuel pressure, bad sensors, clogged CAT, bad plugs/wires, and so forth, so start with the simple stuff and work from there.