Failed emission test due to not complete code

I means that the vehicle failed it's emissions test as it failed the digital trouble code reading test 3
the testing station tests the exhaust emissions and the onboard computer
Your computer failed the test

Computers seldom fail & do not think your
asking about how to repair one

You come here with No Vehicle,year,make model,
test results

Try again

Look at scan tool data-- fuel trim,emission monitors, etc

Find a problem through testing,not just driving it ,work on it

Take it to autozone or another place like it and have them read the codes and tell us what they are.

have the obd codes checked, once they get checked, post the results here, and we will be able to better help you in a solution, I can assist you in defining what the codes mean, and how to repair your vehicle so that your emissions will drop below the required amounts so that you will pass the test

There is a problem with your OBDII (Onboard Diagnostics -2) system. The only way to find out why your Check Engine light is on is to scan your engine computer and find out which part of the system is failing. There will be fault codes stored in the computer to tell you. The failing system will then need to be diagnosed to locate the actual cause of the failure. Once this is completed, the computer will have to be reset, and the car will have to be driven (sometimes for several days) to get all of the computer monitors to run and recheck the system. If the repairs are successful, the same codes should not return. You may have new codes show up however. This is because some of the monitors are unable to run if the check engine light is on due to another failure. Sometimes a code like "Catalyst Efficiency Below Threshold" will show up when they were not there before. This is because driving the vehicle with the Check Engine light on has destroyed the catalytic converters, but the code could not set previously because the catalyst monitor could not run to test the catalyst when the other problem was present. Now that the first problem has been corrected, the catalyst monitor now runs and has determined that the catalyst has been damaged.

This why I tell all my customers that the best time to get your car ready for an emissions test, is the minute the Check Engine light comes on. Ignoring this light and driving the vehicle with it on can damage some pretty expensive parts, as well as possibly costing you fines for not getting your vehicle "Legal" when it is time to renew licenses, etc. I live in Missouri, and you cannot renew your license plates without passing the emissions test - people wait until the last day to renew their registration and they get angry with me when I tell them it is going to take several days and possibly even a couple weeks to get their car to pass. It's not MY fault!!! THEY are the ones who chose to ignore the warning lamp!

How well does the vehicle run?

Assuming that the engine did pass the EGR function test on the emission test results, and the MIL (Malfunction Indicator Light) or check engine light is not on when the engine is running, and if you are not sure when the last time it was that the engine had a complete tune-up, with distributor cap, ignition rotor, spark plugs, spark plug wires, air and fuel filters, then a complete tune-up would certainly help, and if the engine oil and oil filter have not been changed in a while, then they should also be changed before an emission test because long used engine oil traps carbon and it will show up as higher CO on the emission test because the emission analyzer will be able detect the higher CO from the engine oil through the PCV valve.

However, it would seem from those HC readings that there is a vacuum leak, and carefully inspect all of the vacuum lines for any cracks or damage, (especially the vacuum line to the fuel pressure regulator) because cracks in the vacuum lines seem to like to hide underneath the lines.

The emission label under the hood should have the vacuum line routing diagram printed on it, and the vacuum lines should all be checked to be certain that they are all connected correctly.

Here is the firing order diagram for that vehicle to help assist you tune-up the vehicle.

First the fault codes,
U110C is No Fuel Level Bus Message
U0155 is No Cluster Bus Message.
Unfortunatly you have to be able to communicate with the instrument cluster with your scanner to diagnoise and I do not think an aftermarket scanner can do this.

the computer needs to be reset by performing a code erase then drive 500 miles

Your emission sensors seem to be just a 'spec' out of normal (I would not call them defective!), but it could also be tainted fuel. Just to pass test I would buy the gas treatment at your local auto parts specifically for emission testing. Ask them at the counter. It will get you passed.

171 and 174 indicate a lean condition. Your car is commanding additional fuel over the normal amounts and its still not enough and it set codes to tell you it happend on both sides of the engine at once. This can be caused by dirty sensors, old or worn components, plugged fuel filter, dirty injectors...a multitude of things. I could guess, but that gets expensive since I dont have scandata or know what conditions the code set under, and what are the fuel trims under various test modes for comparison. Proper procedure is to scan onboard computer and determine part from collected data. the 775 code is a transmission code.