Eroor code PO455?

[swathdiver]

i dont think it has but im not sure. its an 04 tahoe LT 5.3 v8

Check your RPO sheet: LM7, LR4 (unlikely) or L59 (Flex Fuel). Would originally have had yellow gas cap, not sure about body badges.

 

[rockola1971]

Vin Z(8th character is the engine code) is a FFV. Should have flex fuel on the rear of the vehicle too if it is one.

 

[BlueCollarTahoe]

LM7 with T vin

 

[BlueCollarTahoe]

could these pieces going out make the MPG become worse than its supposed to be?

 

[BlueCollarTahoe]

it got up into the 50's in NYC today and BAM the code came back. gonna swap out all these pieces and report back couple weeks SMH. ordered the pieces swapping out next week.

 

[BlueCollarTahoe]

bump

 

[oldchev]

I had this irritating code. Gas cap was nofix. The vent valve in the rear was the issue first time. I tested it on the bench with 12v to apply and release. Seemed fine dust/dirt was in the solenoid keeping it from working. I used air and spray cleaner to get it working. Without resetting and clearing the code it reset itself after a few miles. I eventually replaced it. The next time this happened it was the purge valve on top of the intake manifold. That was not working no matter what so I replaced it. Next would be a "smoke test" to verify if a vent line was cracked or leaking. Smoke would also have found the open vent valve.

 

[Rocket Man]

I had this code twice. Both times it cleared on its own though but the first time I found a TSB about fine dirt clogging the vent valve if you drive on dusty roads which I do at times so I changed it. It didn't look dirty. Then a year later the code came back but I think it was just a gas cap that wasn't tightened all the way. It went away and hasn't come back. The code not the gas cap lol.