mpsjr
Well-Known Member
I posted this earlier in the Gen1 section, but haven't gotten any responses yet, so I figured I would post it here as well.
A few months ago my fuel pump died, so I had a local shop replace it. A couple of weeks before, I'd had the same shop clear an O2 sensor code before we went on a long trip (2,400 miles). My truck had been parked for several years before I got it, so the O2 sensor issue wasn't a surprise.
When I picked my truck up after getting the new fuel pump installed, my Service Engine Soon light was on. At first, I figured it was just the same O2 sensor issue that it had before the fuel pump went out so I didn't pay attention to it at the time. I eventually got it scanned at Autozone and they said it was DTC P0452.
What complicates things is that I also noticed a hesitation problem with my truck after getting the new pump installed. In fact, it died as I was pulling out of the shop's parking lot. It never had the problem before, and I initially thought it was just air trapped in the line from having the new pump and filter installed. However, the problem never corrected itself, so this past weekend, I decided to put in another pump since the other one was still under warranty. Since the only change was the new pump, I thought that had to be the problem. After getting everything back together on Saturday, the DTC light was gone (THRILLED) as was the hesitation/stalling problem. However, on my way home this past Monday, the CEL came on for the same P0452 issue.
My question is whether anyone knows what could be causing the problem, considering the symptoms it has, and the work that's already been done. I know the code is for low voltage at the FTP sensor, which could mean any number of things, but being that the voltage is low, I'm figuring it is probably a plugged solenoid or canister vent. Does this sound about right? I have checked the hoses and connections going to the EVAP canister and everything seems fine, and yes, my gas cap is on (I actually replaced it about a month ago). I do (sometimes) get a hissing sound when I pull the gas cap off after driving, which I know can mean the EVAP canister vent is blocked, but how would I go about fixing the problem. Should I be looking at something else first? Any help would be greatly appreciated.
Thanks in advance.
Matt
1999 Expedition EB 4x2 5.4 (190,***)
A few months ago my fuel pump died, so I had a local shop replace it. A couple of weeks before, I'd had the same shop clear an O2 sensor code before we went on a long trip (2,400 miles). My truck had been parked for several years before I got it, so the O2 sensor issue wasn't a surprise.
When I picked my truck up after getting the new fuel pump installed, my Service Engine Soon light was on. At first, I figured it was just the same O2 sensor issue that it had before the fuel pump went out so I didn't pay attention to it at the time. I eventually got it scanned at Autozone and they said it was DTC P0452.
What complicates things is that I also noticed a hesitation problem with my truck after getting the new pump installed. In fact, it died as I was pulling out of the shop's parking lot. It never had the problem before, and I initially thought it was just air trapped in the line from having the new pump and filter installed. However, the problem never corrected itself, so this past weekend, I decided to put in another pump since the other one was still under warranty. Since the only change was the new pump, I thought that had to be the problem. After getting everything back together on Saturday, the DTC light was gone (THRILLED) as was the hesitation/stalling problem. However, on my way home this past Monday, the CEL came on for the same P0452 issue.
My question is whether anyone knows what could be causing the problem, considering the symptoms it has, and the work that's already been done. I know the code is for low voltage at the FTP sensor, which could mean any number of things, but being that the voltage is low, I'm figuring it is probably a plugged solenoid or canister vent. Does this sound about right? I have checked the hoses and connections going to the EVAP canister and everything seems fine, and yes, my gas cap is on (I actually replaced it about a month ago). I do (sometimes) get a hissing sound when I pull the gas cap off after driving, which I know can mean the EVAP canister vent is blocked, but how would I go about fixing the problem. Should I be looking at something else first? Any help would be greatly appreciated.
Thanks in advance.
Matt
1999 Expedition EB 4x2 5.4 (190,***)