[Juvat]

Lately, my truck's been throwing out a code (P0452) every couple of weeks and I was wondering exactly what to do about it. I've looked it up on-line, but all I get is, "Evaporative Emission Control System Pressure Sensor Low Input."

After the code is thrown and the light comes on it'll stay lit for a couple of hours, possibly a day or two, and then it will go out. This hasn't happened over the last couple of weeks, but I've noticed that my mileage has dropped significantly (from 13.5 to 12.5) and I need help figuring out what might be wrong and how I can fix it.

'99 ECSB K1500
5.7L
132K

 

[2004JGPSilverado]

Check out this site. www.obd-codes.com
Lots of good info there. With out more info, kinda hard to say. Most likly cause is the EVAP pressure sensor going bad. This is the most likly, but deffinantly not the only thing that can set this code.

 

[Juvat]

When I had the code read at Autozone, the code reader said it was a fuel pressure sensor (of course they tried to sell me one on the spot!) which conflicts with what I've found online so I didn't know at first to be looking into the evap system.

Here's as much more detail as you're going to get:
The first time the code kicked out, I was only doing normal around town driving. Light stop and go and I wasn't being a lead foot. Now, I've also noticed when I'm a little higher in the RPMs before the final upshift (usually between 70-75mph) that the truck starts running slightly rough. Kind of like it wants to shift, but won't and it's bogging down a little bit. There's definitely a huge loss of power when this happens and if I let off the gas for a few seconds it'll subside and the truck will finally upshift as soon as I give it some gas again.

Any ideas now?

 

[Juvat]

No one has a clue, eh?

 

[kawamatt2]

Here ya go bro.

 

[diehrd]

Make sure gas cap is tight

 

[Juvat]

Make sure gas cap is tight

That was the very first thing I did, followed by disconnecting the battery to reset the computer.

Appreciate the info a lot, Matt. It definitely gives me a good starting point.

 

[kdubbz]

My truck just recently got this same code, I thought it was the old one I had that I fixed by replacing the vent solenoid and the canister, but I scanned it and its P0452. Damn emissions, messing me all up. I cleared the code and it came back instantly, now a week later code is still there, wont go away so I am going to order that fuel tank pressure sensor. Also btw, does anyone know the part number for the FTP sensor and who sells it? Thanks.

 

[kdubbz]

Just thought I would post back, I replaced this sensor that I got at napa for $45, expensive for a stupid little emissions sensor. went to advanced, cleared the code and it dident come back. napa part number is CRB221001
or these others
GM #16238399
Standard AS302
Borg-Warner EC2501