I just bought a 02 S40, with 75K miles. The dealer said he had the car serviced before I picked it up. Anyway, on the way home, the check engine light came on. I had the code read: PO171 -(Bank1) system too lean.

It seems to run fine, as I said, we just bought it, so there is no reference for before the light came on.

What causes this and what are the fixes?

Thanks!

 

"too lean" would probably mean the air/fuel mixture is off. If you JUST bought the car, I'd tell the salesman to fix this; even if no warranty i'd explain that you both want to walk away from the sale happy and it's the right thing to do. Causes... could be a leak in intake, bad O2 sensor..etc

 

I agree take it back.

 

Auto zone read the code, suggested I put injector cleaner in.

About 3 days later, the light went out and it has stayed out.

 

hi i was getting system running lean eventually car wouldnt start.at all. injectors pulsing,pump priming and spark but no start replaced fuel regulator and car going.re set fault codes and p0171 code gone all well...james

 

Got fault code P0171 and simply removed the Mass Air Flow sensor, MAF, an $82.00 part, cleaned it with spray brake fluid, replaced the O-ring and reinstalled the part ( 2 screws ) and corrected the check engine light fault code. Simple job, $6.28 cost. Hope this post finds it's way to help others.

 

In my previous post I said spray brake fluid but meant spray brake cleaner.

 

10 yr old post

 

I agree with you my friend