Let me preface this with before yesterday, the only thing I've ever done is checked and added fluids to my car.

Failed inspection (emissions):
GAS - Max / Reading / Result
NOx - 1323 / 2771 / FAIL
HC - 173 / 133 / PASS
CO% - 0.98 / 1.70 / FAIL
CO2% 12.7
O2% - 1.3

So, I changed the PCV valve and air filter, did an oil change (I was basically right at the 3k mile mark). Of course, I was hoping the quick and cheap fixes would bring it down. Also, I was overheating the day of the tests so I topped up my fluids and replaced my thermostat with a new one (no more overheating). New results?

GAS - Max / Reading / Result
NOx - 1323 / 2391 / FAIL
HC - 173 / 181 / FAIL
CO% - 0.98 / 1.09 / FAIL
CO2% 11.7
O2% - 1.1

Soo, it looks like my CO went down significantly, and my NOx decreased some, but my HC went up a little. Alright, so now I feel like an idiot for wasting my time without doing more work first. I bridge the little pins on the ECU and switch my key to ON.

blink blink blink... code 41! Oxygen sensor heater. (No other codes exist, just code 41) Now, is it my understanding that with the o2 sensor heater faulty, the engine runs in "open loop" mode, which probably has alot to do with me failing emissions.

But doesnt the o2 heater only matter while the engine is cold? Once I drive around for say, twenty minutes to half an hour (the time i drove from home to the inspection station), shouldnt the O2 sensor be heated up and properly functioning?

I'm just wondering if the hundred bucks for a new 4 wire sensor is gonna fix my problems. Also, I cant figure out where the sensor is wired to so I can disconnect it and test it with a voltmeter...

Also, is there anything else I should do? I'm a complete noob to car repair.

Thank you.

PS - how many times am i allowed to fail inspection?

 

Well I don't know anything about the HC or CO% emissions you failed, but a BIG possibility for that NOx fail could have to do with your EGR runners. I have a '91 Accord and when I did my last emissions test I failed the NOx. Was told clogged EGR valve or EGR runners can be a major contributor. Next thing I know, a mechanic friend tells me I need my EGR runners cleaned.

When you accelerate from a complete stop, does the car kinda do a "b...b..bump..." feeling real quick at the beginning? That's a definate sign of it.

 

Well, given the code you threw, you probably need a new oxygen sensor. It's probably been running rich for so long that the cat is also trashed. Given those number you have, the cat is probably toast. But make sure you do the sensor AND the cat. The cat is now bad because of the bad O2 sensor.

The numbers you have are pretty much what my 92 had with a dead catalytic convertor. My O2 sensor was trashed so I replaced it and had it checked again. The Nox only went down 200. Then with the new cat, it went down to 63 from 2600. The inside of my cat was a solid black mass. There was a hole in it from where the part had broken off of my O2 sensor.