P0455 Cont

[Zackie]

Okay so, I posted this a little while ago about my sport having a P0455 issue, and it’s gotten a lot worse now, I’ve now replaced the following: Fillerneck, Purge Valve, Gas cap, the rest I don’t remember as it’s been a minute now but basically all the most common stuff, at this point the vehicle is now backfiring and badly, I’ll be going to get onto the highway and it’ll sputter and struggle to get up to highway speeds now and I don’t know where to go from here

 

[C420sailor]

What are your fuel trims?

Have you checked all the lines, end to end?