fault codes, faile smog

[rasczak]

I have a 98 integra that just failed smog because the check engine light was on. The codes were lifted and I was given a p0420 and p0302 code.

P0302 Cylinder 2 Misfire Detected
P0420 Catalyst System Efficiency Below Threshold (Bank 1)

funny thing is when I looked at the pass/fail indications, the cat converter passed. So I'm kinda confused as to where to start with this. Any ideas would be great.

Thanks!

 

[LTC8K6]

Fix the misfire first. Plugs, wires, coil...whichever your car has.

 

[Bignate603]

I agree, fix the misfire first. I've had a cylinder misfire in the past from a plugged injector. The cleaning on that was more expensive than it will cost to replace all the plugs, coils, and wires in ignition so I'd start with the cheap stuff first to see if that fixes it.

 

[kornphlake]

I have a 98 integra that just failed smog because the check engine light was on. The codes were lifted and I was given a p0420 and p0302 code.

P0302 Cylinder 2 Misfire Detected
P0420 Catalyst System Efficiency Below Threshold (Bank 1)

funny thing is when I looked at the pass/fail indications, the cat converter passed. So I'm kinda confused as to where to start with this. Any ideas would be great.

Thanks!

The P0420 code indicates that the cat isn't okay, at least not to the manufacturers specs, perhaps the state allows a lower threshold. This isn't the code you'd see if the or Air Fuel sensor was not working properly, P0420 means the sensor is working correctly but something upstream isn't. Fix the misfire issue first since it's the easiest and cheapest. There's a good chance the code both codes will go away at the same time.

 

[rasczak]

thanks guys, I'll take a look in the morning.

1. replace plugs and wires.
2. clean fuel injectors. (seems like a risky job. is this something I could do on my own as a novice?)

3. ?
4. ?

 

[Bignate603]

thanks guys, I'll take a look in the morning.

1. replace plugs and wires.
2. clean fuel injectors. (seems like a risky job. is this something I could do on my own as a novice?)

3. ?
4. ?

There will be more to the ignition system to try if the plugs and wires don't fix it. Get a Haynes or Chilton manual (tip: Many libraries stock them for popular makes and models) and see what other ignition components your specific car has.

I had a mechanic do the out of car injector cleaning. He had equipment for it that you're not going to have. You could replace the injectors yourself if you wanted but I'd expect it to be around $50 per injector.