Well I go to get my Emissions Test and right before I get there my Service engine soon light comes on im like aw crap. I took the test because If you fail the next is free anyway... So I failed because I had a "System too lean," The guy said I could have a clogged fuel injector or a Faulty sensor. Im a bit worried but the next day the light turned off and I went and passed the test. Should I worry about it?

 

It's good to know what the code was and should still be stored for 40 cycles or so. Find out what the code was, if nothing else for future reference in case you notice hugh power or loss or if fuel consumption increases, etc.

 

typically that will happen periodically, i know because it has happened to me a couple times. i just use my snap-on scanner and monitor my oxygen sensors if they check out fine then i just clear the code. typically what will happen is the oxygen sensor gets a lean reading then it sends more fuel to adjust the mixture to be safe. it could be many things that would cause that. i would just perform a fuel injection test or if you want to be cheap run a cleaner through the fuel system.