Failed the LOW SPEED Texas Inspection, what do i??

[14mins]

For the 1st time in years i failed the Texas State annual inspection. In years past it has always been close but i have sqeaked by without a CAT on the car. This year the LOW SPEED EMISSION RESULTS (15MPH) failed and pretty bad. I passed the HIGH SPEED EMISSION RESULTS (25MPH) although it was close. I have all the basic upgrades on the car.

My 87 GN was not driven much last year and the gas in the car was about 1 year old although i did top it off with a 1/2 tank of fresh fuel. I changed the plugs and oil for thrills also. I put the factory chip back in and backed the fuel pressure down a bit. I have green stripe injectors (30 pounds??) Car has 140.000 original miles on it and i have owned this car since 1990.

THE LOW SPEED THAT I FAILED- Report shows RPM's to be at 1106 and the HC (ppm) was 281 and i had to be below 152. The CO (%) was 1.96 and had to be below 0.86 everything else was fine and way below the maximums with the exception of the HC (ppm) on the high speed (rpm 1188, 25 mph) . I scored a 143 and the max is 148 for that part.

Car for the most part runs great and the sensors are within specs acording to the scanmaster.

MY OXYGEN SENSOR IS probably 6 years old with 50 k on it, i have Taylor 10mm spark plug wires and used AC/delco plugs and run a K@N air filter.

What is my low speed issue? What do i need to do to pass? Can you get a "EMISSION CHIP" burned to help? I do not post a lot on here but do pop in a few times a month to read what is going on. I would rather figure out why my low speed was so high rather than cover it up just to pass the test. I do not mind getting dirty and working on my car. For years my car ran terible and the people on here helped me get this car to running better than the day i originally bought it.

Thanks

 

[aminga]

YOu put the factory chip in with what size injectors?

 

[TurboTnZ06]

The chip needs to be calibrated for the injectors. A stock chip with bigger injectors will probably cause it to be richer=fail.

 

[pmoore4321]

If you can make it Jan 1, 2011....your GN will be emissions exempt.

 

[14mins]

I look foreward to the day i no longer have to pass the test.

I have always used the stock chip with the 30 pound injectors when it come time to inspect.

I am looking for the issue on the low speed. I have not done much for the last 5 years, 35-40k miles.

My 02 sensor, coil pack, IAC and all are many years old now.

Is it something as stupid as air filter oil on the mass air flow sensor? Should i run a can of injector cleaner thru the fuel rail? I hate wasting money so i do not want to make uneducated guesses.

I do not think my 02 sensors cycles as fast as it used to.

I also have razors alky kit on the car, not sure if that is in my profile or not. I figured alky was good for the car, it is good for me.:biggrin:

 

[charlief1]

I'm in Hillsboro if you want to put it on a scanner. I'd say add some E-85 into the mix after you drain the gas out of it.

 

[davidf]

If you can make it Jan 1, 2011....your GN will be emissions exempt.

Thats good to know although we don't test down here.

 

[14mins]

I just looked, i have been here 8 years and have 82 post.

Does the o2 sensor have anything to do with this or is this a timing deal?

Should i run the car hard and get it all hot before retesting or the oposite?

 

[Perpendicular]

Mine failed too

I have had a few inspections done in the past year, several cars, several failing.

My experiances are :

When I failed it was usually a problem with the car being cold (if it is close to failing to begin with) - Run it hard for 20 minutes or so with fresh gas.

Don't idle it for too long when you are about to get it through the smog check.

Check all of the vacuum lines. It could have a leak and cause the system to compensate for it at idle. Had that happen too.

My T-Type did the same as yours, really bad at idle but good at higher speed. I could never find the issue until I did a compression test and found one out of the 6 at 80. Others were at 140 or so. I really hope this is not your problem.