I have an '03 S40 with 68k on it. Two months ago I had it inspected and had code P0445 (Large evap leak). The garage (not a dealer) cleared the code and said it could possibly re-emerge. Well it did, While the CEL was on, I noticed that fuel gage was off. With a full tank, the digital display would read 295 miles DTE. When the low fuel light came on, I decided to run the car until it was out of gas, (ran another 100 miles- for a total of 400 miles/tank on hwy/city driving). I filled up the tank and the CEL went off but I still have the same mis-reading on the digital display. My question is, can the P0445 code still be an issue with the cel off and could this be causing the digital gauge to give a false reading or is this a totally separate issue? If it would be separate issue is it something I can fix or does it need to go a dealer?

I never had this problem when I purchased the car in Sept. '08. It only occured after I got it inspected.

 

They are seperate issues.
I believe the dealer can calibrate the guage. Has been a known problem.

A bad gas cap can cause that code.