P0452

[Royal Thunder]

I know this code has been posted and asked about before. I just want to get other opinions before I drop the tank again and start slapping parts in.

First the specs: 1998 K1500 Silverado 5.7 vortec Z71 130k on the dial

The tank, fuel harness, and pump was replaced by the stealership I bought it from. The first time I had the P0452 it was with a bunch of other codes relating to the evap system. The filler neck wasn't on all the way so it leaked and when I put it back on the codes except for the p0452 went away. Still had a fuel leak and today I had all of the fuel lines and evap line replaced with nylon lines. So no fuel smell anymore but the P0452 code still remains. Took the fuel cap off and put one on that I new was good, cleared codes, and drove a couple hours. Light stayed off for awhile then came back on. Same P0452 both pending.

I don't smell fuel leaking and it doesn't run rough. Am I right in assuming the FTPS dying?

 

[df2x4]

Check the electrical connector on top of the EVAP canister under the hood. Should be on the driver's side. Mine was loose on my red truck, causing intermittent EVAP codes.

Short of that, you may want to take it to a shop and have the system smoke tested. Sucks because it takes time and money, but you'd still probably be money ahead compared to just throwing parts at it. EVAP codes are a major pain to diagnose.

 

[Royal Thunder]

Checked the plug on the canister and the plug over by the TB where the purge line connects to the engine. All snug and clean. Couple things I noticed, when I clear the codes the P0452 code returns instantly. The truck is not running just the key turned forward. That is the only code I get. I also don't get the hiss when taking off the fuel cap. I looked at the gasket on the cap and noticed a few dry spots and the rest of the gasket is wet. I will pick up a new cap Friday just to eliminate the cap altogether. I am also noticing the gas mileage is worse since I put the new lines on (1/8th of a tank in 36 miles).

I am thinking of taking the truck back to the shop and have them look over everything just to make sure they connected all the lines and harnesses correctly. No point in chasing down an issue if it is a loose fitting on one of the new lines.

 

[Royal Thunder]

Update. The shop tested everything and it is the FTPS. Now just waiting for some nice weather to drop the tank.