asticot

Hi all,
Was driving to the store and the check engine light turned on followed by the three VSC lights.

When I turn the car off then on, Check engine comes first followed up by the VSC lights.

car drives and sounds fine. I used a scan tool and pulled the following codes

P0420
C1201
C1223
C1241

read a little bit and I tightened the gas cap already. Next step will be to replace the cap.

It’s an 06 with 140000miles.

anything else this could be? Read up on P0420 and that relates to O2 sensor or Cat. I just had this car safetied in September and it underwent thorough inspection

jpnut

This happened to me and I changed the gas cap with no luck. First two cats are on the way out. My mileage is 141k as well on an '03. Indy shop said its about right given the mileage. Good luck. BTW, the gas cap was long overdue, the new one is much better seal (From Amazon)

asticot

Hopefully I have better luck than you. I recently changed the drivers side exhaust manifold because of a leak there. As I understand the P0420 is for Bank 2 O2 sensors (I don’t know which one though, my reader doesn’t tell me that) which is on passenger side, and that manifold/cat weren’t touched.

everything I’ve seen so far hopefully points to a gas cap issue as it’s not just the CEL code but also the VSC lights that come on. If gas cap doesn’t work, I’ll be changing the O2 sensors next.

asticot

I ordered the gas cap, and in the meantime cleared all the codes. Drove the truck today for 35miles both stop and go and regional hwys and lights did not return. I tightened the gas cap pretty good. Fingers crossed that these lights don’t come back.

Today I also noticed some noise from the alternator. Reading some posts online, I understand that an alternator on its way out could throw some of these codes. I don’t have a multimeter to check, although my battery is brand new and I haven’t sensed sluggishness at start to suggest parasitic draw; I also don’t drive the truck every day and with the new battery it starts right no matter how cold it is.

I’ll keep people posted on outcomes

jpnut

Thanks for the update and I will have the tech look at the alternator as I am going for an oil change on Tuesday. Appreciate the digging around. I'll share an update when I get it.