Got the dreaded P0455 code... again..,

[Steve Waddington]

So I have this 20.00 scan tool that reads and clears codes. The last time I got this code, two weeks ago, I replaced the gas cap and cleared the code, and thought that was it. Last week it came on again. I tightened the gas cap, cleared the code... and it’s on again as of last night. So, it ain’t the gas cap ! Lol.
There are SO MANY other things it could possibly be! But before I start replacing each part one by one...
Is there a relatively inexpensive scan tool that will pin-point what the exact problem is ? P0455 is such a generic code!

 

[Steve Waddington]

Maybe something I can use with my iPhone 7?

 

[Doubeleive]

most likely either the canister is plugged or one of the solenoids has failed or is failing, the front solenoid runs about $33, the rear about $50, canister is more expensive around $150
mine recently turned out to be the front solenoid. usually people just shotgun it and do all 3 because the cost of a diagnostic and labor and 1 part is almost the same if you just purchased the 3 parts and do it yourself. I would start with the rear solenoid and unplug it and see if any little round pellets come out of the hoses if you have loose pellets then do all 3 parts and blow out the lines with air while everything is all disconnected, if no pellets then you may get away with just doing a rear or front solenoid. I have a tech2 and tried to do a evap test but it turned out to be kind of a pain because it has to have just the right conditions (key off/on just right, cold temperature and rpm's 1800-2200 for the entire test) after several tries I just said screw it.

 

[Erickk120]

Yup, from the threads of that code it ends up being one of those 3 parts most of the time if the lines are fine. I shotgunned mine and did all 3 parts with AC delco ones, and its been over a year with no codes. 150ish for the canister, and like 30 and 15 for each of the solenoids

 

[MCAT069]

Check Amazon. Got all three items for like 70 bucks shipped; the canister was open boxed.

 

[Rocket Man]

I keep getting the same damn code. Replaced the rear solenoid, then the gas cap and now I just ordered the front one at the intake manifold which happens to be a supercharger now and the one there has a part number off an 08. I'm not sure if Whipple supplied a different part when I installed the blower but I ordered the one that's there now.

 

[willinnashville]

I had this problem a couple years ago and it ended up being the front solenoid. I replaced the canister and gas cap which didn't fix anything, and was really hoping it wasn't going to be the one on top of the gas tank. I ended up getting lucky it was the front.

 

[donjetman]

Yup, from the threads of that code it ends up being one of those 3 parts most of the time if the lines are fine. I shotgunned mine and did all 3 parts with AC delco ones, and its been over a year with no codes. 150ish for the canister, and like 30 and 15 for each of the solenoids

Eric, I recently got the check engine light(P0455 code) on my 07 6.2 Yukon Denali. The previous owner had recently changed the ACDelco 23481275 GM Original Equipment Vapor Canister Vent Valve($35 amazon) but the code came back, so I replaced the gas cap w/ACDelco# GT350 ($19 amazon) and the vapor cannister purge valve, located on top of the driver side fwd valve cover, w/ACDelco# 214-1680 ($19 amazon), so far so good.

 

[Erickk120]

Yeah, seems to be a common problem, some people don't mind the CEL on but it makes me go nuts when I see it on in any vehicle I've owned. My uncle has driven his 2001 since new and he has been living with CEL since 2008 after he replaced his gas pump and cracked one of the EVAP lines that runs around the gas tank, madman never bothered to change it.

 

[Rocket Man]

Yeah, seems to be a common problem, some people don't mind the CEL on but it makes me go nuts when I see it on in any vehicle I've owned. My uncle has driven his 2001 since new and he has been living with CEL since 2008 after he replaced his gas pump and cracked one of the EVAP lines that runs around the gas tank, madman never bothered to change it.

Well the problem with that {besides the obvious one that it’s annoying) is there’s no way to know when another problem pops up and also throws a code. You’d never know unless you check codes every few days to make sure nothing new has come up.

 

[Doubeleive]

mine was the front recently as well, it's been over a week since I replaced it and no more "tighten gas cap", actually I just put the original one back on and the "standard brand" I had put in over the summer must have went bad already.

 

[Rocket Man]

I just replaced my front today. Fingers crossed.

 

[latvius]

I've replaced everything at least once and I still get "tighten gas cap" at about 3/4 tank or less. I've replaced the front once, the back solenoid twice, the charcoal canister, the gas cap, put a smoke test on it....
Hope you all come up with something I can use that I have not heard of

 

[Doubeleive]

I've replaced everything at least once and I still get "tighten gas cap" at about 3/4 tank or less. I've replaced the front once, the back solenoid twice, the charcoal canister, the gas cap, put a smoke test on it....
Hope you all come up with something I can use that I have not heard of

possibly a cracked line or one of the parts you replaced is no good

 

[Rocket Man]

Well shit I just got P0446 tonight on the way home from work, which is vent control valve circuit malfunction. This is irritating. I replaced the vent valve not too long ago. I wonder if it's the canister or a cracked line. I did drop my tank and replace the fuel pump a few months ago and I pulled the canister when I did that but this problem just started showing up few weeks ago.

 

[live2pull]

Well shit I just got P0446 tonight on the way home from work, which is vent control valve circuit malfunction. This is irritating. I replaced the vent valve not too long ago. I wonder if it's the canister or a cracked line. I did drop my tank and replace the fuel pump a few months ago and I pulled the canister when I did that but this problem just started showing up few weeks ago.

I have done this same thing on my 2004. I did not drop the tank however, I have not replace the canister (yet). I have heard that the tank pressure sensor could also trip this code. The PITA of this is you have to drop the tank again. I'm torn between dropping the tank for the sensor or biting the bullet on the charcoal canister.....

 

[Rocket Man]

I have done this same thing on my 2004. I did not drop the tank however, I have not replace the canister (yet). I have heard that the tank pressure sensor could also trip this code. The PITA of this is you have to drop the tank again. I'm torn between dropping the tank for the sensor or biting the bullet on the charcoal canister.....

Tank pressure sensor? I replaced the entire fuel pump module with an AC Delco so there’s nothing left in the tank for me to replace. I haven’t got another code in over a week though so maybe that one was from replacing the front part, fingers crossed.

 

[live2pull]

Tank pressure sensor? I replaced the entire fuel pump module with an AC Delco so there’s nothing left in the tank for me to replace. I haven’t got another code in over a week though so maybe that one was from replacing the front part, fingers crossed.

From what I've seen the pressure sensor is on the exterior near the lock collar. Quite possible the vent solenoid could solve the problem. Also, the pressure sensor could be on the 03-06 models only, but don't take my word as gospel.

 

[Rocket Man]

Duplicate post. Stupid glitchy forum.

 

[Rocket Man]

It’s

From what I've seen the pressure sensor is on the exterior near the lock collar. Quite possible the vent solenoid could solve the problem. Also, the pressure sensor could be on the 03-06 models only, but don't take my word as gospel.

If it’s on my 02 it’s included as part of the module. I see the plug for wiring on it and that looks like the plug on my fuel pump module. There’s nothing else on the top of or inside my tank to be replaced. Here’s a partial description of anotherAC Delco FPM from Rock Auto so it seems if there’s a pressure sensor, it’s included. I’ve replaced both vent solenoid and purge solenoid as well as gas cap.
GM Original Equipment; Includes Sender; Includes pressure sensor, Fuel Sender o-ring seal, internal strainer, fuel ... ACDelco GM Original Equipment Fuel Pump Modules consist of an electric fuel pump and a jet ...