Failed Emission Test, Misfire P0313 code help!
 

Hi,

I failed emission test today (WA state) with the following error codes
P0313 Misfire Detected with Low Fuel
P0172 System too rich Bank 1
P0174 System too lean Bank 2
No actual performance loss seems on the engine.

What could be the problem? What should I check or change? air filter, oil (been replaced 500 miles ago), spark plugs etc?

DG

electronic fuel injectors. i think you can test them with an ohm meter.

Ok chcked all spark plugs, all in good condition, put a new air filter. Nothing is different. SES light has been on for 10000 miles now, mechanic said that as it came on 60000 miles, this is a regular second service check just ignore it. He did 60K service.

Do these emission control people just plug in OBD II to the connector and read of error codes? Or are they actually measure emissions? Can anyone shed light to these error codes and how to reset these?

Not sure about how they do your emissions test since I am not sure where you are located. I know when I lived in Wisconsin, since it is an all wheel drive vehicle, they just checked the vehicle for codes but when I was in Germany they actually had the vehicle I had at the time on rollers and used a probe in the tailpipe to measure.

You should be able to go to any local parts store and "borrow" a OBD II scanner. Usually they will reset the codes for you.

check the spark plugs. I had a leaking valve cover gasket. oil leaked into the chamber where the plugs and coils are and some misfires too place which gave me the SES light. IIRC I got similar codes.

After you checked everything (spark plugs, wires) did you erase the codes?

fast4d - I had the same story - oil spill in the engine as those idiots at the oil service did not put the cap on the oil filter properly. Lost a couple of quarts. Engine was cleaned after, a bunch of error codes came: low oil pressure and misfire. I guess they had to be cleared out.

youry - no, the codes were not cleared.

that's the problem I had two weeks ago. I had to add some oil and of course I forgot to put the oil cap back. I ordered the cap online and by the time I got it I used duct tape to cover the hole. erased the codes and no engine light since. try erasing the codes! see if they come back.

Just an update. Simply cleared the codes in Autozone. Nothing comes back. SES light is gone, ODB II needs some more time for emission control. I guess needs various driving pattern to collect data.

As of what I know for sure misfire test has passed through, as 2 out of 6 ODB tested already passed.

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Here is my point: why in the world the idiotic state emission control is using your automobiles ECU to detect the problem? They should measure directly the CO level and thats it. Nevertheless they do not even test your car for emissions if they see some, turned out to be old MIL codes.