05 OBXT engine codes

New here, I was sitting in the drive through and my check engine light came on, as well as my cruise control light. I immediately went to Autozone and had the codes read. I got P0171, bank 1 is running lean and I had a misfire in every cyclinder. My car is bone stock aside from the intake silencer delete. Any ideas? the kid at Autozone told me me to check my fuel filter and I've seen stories of other cars running bad gas, running it to empty, filling up, and everything being fine.

What is the mileage and fuel type used?

I've seen my Subarus throw odd codes, even though the car seemed to be running OK. When that happens, if the code is not reporting a major malfunction, I delete the code to see if it comes back.

If the code keeps coming back, there is a problem.

 

I've ignored minor problem codes that never came back, or only returned at irregular intervals a couple of times after deletion and it never caused trouble.

 

Once my OBXT started running rough and it threw a code for a problem with the tumble gate generator. Next time I started it, it ran fine so I deleted the code with no further problem in several years.

 

Years ago, my Impreza threw a few codes about the O2 sensor being slow to warm up. I deleted them, the codes quit appearing and there was never a problem.

The OBDII is not completely foolproof.

 

On the other hand, when the Impreza began displaying the code for a bad knock sensor, it didn't take long for the code to reappear when deleted. I got that sensor replaced quickly.

 

If the car is running OK, you could try a fresh tank of gasoline to see if it helps. If your fuel filter has never been changed, now is not too soon.

 

Good Luck.