Problems

[owenbyc]

hey everyone, how ya'll doing today? i took my truck yesterday to have it fixed at a shop.i had a light on that was a po455. i read it it was a emissions large leak so i changed the cap allready to a brand new one so i knew that wasnt it. ive been having a p0446 which i think was the vent valve malf. if not that was the description i was getting. my fuel pump went out about a month ago so we pulled the bed and changed it out no problems. now right after i got the pumped changed no more p0446 but the po455 large leak. so at the shop yesterday and they pulled the tank and they found a emission line at a "t" that was broke. so they fixed it i dont know if they rigged it or what. left yesterday they ran it no lights or anything i drove it to the gas station on the way to the house. i filled up and left to go home not even 50ft i get a new code a po453 fuel pressure sensor high. its one damn thing after another lol. i cleared it and its came back on twice. so is this all related i dont think the code is saying the sensor could be bad but also this is a brand new pump with sensor on it. i still want to do the vent valve filter relocation and all that but damn what to do next. any help guys would be greatly appreciated thank you so much. oh yeah its a 03 4.8 4x4

[hrspwr]

I would assume that it has something to do with the tank vent. Try leaving the cap loose just a bit so some pressure can leak out. See if that resolves the issue. If it does, then your tank vent it clogged or not opening properly.

[dlewis1111]

similar issues on my 08. dealer told me to stop "topping off" the tank because they think that is getting the vent valve wet and causing the codes that I was getting.

[owenbyc]

hey hrspwr when you mean vent do u mean the vent valve? ill try the cap.its kinda funny you said the dlewis i filled her up yesterday. i let it kick off then i didnt add anymore. damn problems you actually break down and pay someone else and they might fix that problem but then maybe create another maybe its just bad luck lol. thanks guys for all your help.

[hrspwr]

If I am not mistaken there should be a a breather on top of the sending unit, or a vent that controls the amount of pressure in the tank. I know on my brothers blazer his problem was that he did not have enough pressure(pressure was escaping from around the actual sensor). If you loosen the gas cap that should purge some of the pressure, but may take too much out and cause a low pressure code. So getting the right tightness is going to be a pain to see if the code goes away. On the good side of it all, if you clear the high pressure code and you get a low pressure code, then you know exactly what it is.

[tanked_darren]

similar issues on my 08. dealer told me to stop "topping off" the tank because they think that is getting the vent valve wet and causing the codes that I was getting.

 

YES +1

 

 

 

BTW there is tons of info on this if you look in the "how to" and the "ask a GM technician" areas.

[minibike132]

The P0453 has nothing to do with restrictions or leaks in the system. This is a purely electrical code. The PCM puts out a signal to the tank pressure sensor and reads what comes back. If the value that comes back is unreasonable this code sets. This particular code means that it's reading above 4.9volts meaning there was no drop. Since someone just had the tank down for repairs and the code sets constantly I would say they left it unplugged, pinched a wire or dammaged a connection. I would take it back.

[jro909]

it clearly says in the owner's manual and gas pumps not to top off

[owenbyc]

Thanks everyone. Hey sparkstech your dead on man. But now i kinda dont trust the mechanic. Hell say ahh this wire was broke or burnt and charge me another 200 to pull the tank. I would like to pull the bed myself again and check. Is there a way to check the wires and sensor with a volt meter or ohm meter. Thanks so much. Fix one problem create another

[owenbyc]

i even kept the old sensor off the other pump. so maybe if it was bad i could just change it out

[owenbyc]

I went out there this morning to look under the truck. I checked the pressure sensor was still plugged in. But now im pissed off. The whole front of the tank was hanging there they didnt even bolt the front strap back on. Luckily the bold was wedged in on the frame beside the tank. Do yall think when i filled the tank after i picked it up that the gas maybe went in the vaccum hole on the sensor. It was leaning pretty good. Wtf man pay people good hard earned money and they do this $hit

[HawkScot]

Sounds like you might have found your problem, hope that takes care if it.

[owenbyc]

Hawkeye you think that could have been it