P0455 Cadillac Code - Evaporative Emission System Large Leak Detected

replaced the evap canister the selnoid behind it, the gas cap and the purge valve up fron on the throttle body. Im still getting the code

What model and year is your Cadillac?

I have an 08 Escalade ESV V-8 base model. I have an error code P0455. I have replaced the vent solenoid valve. I'm still having an issue. I have pressurize the system from the canister through the tank to the gas cap. I've use the soap bottle to identify any leaks and found none. The system seems to be holding pressure. I can smell fuel leaks in the system but can't identify where the leak is coming from. I have tested the voltage to the solenoid valve and get between 12 and 13 V. Any suggestions on where to look next.

There is factory service bulletin for that code. The bulletin recommends replacing the Fuel Tank Pressure (FTP) sensor, but if you smell gas you may have a leaking gas tank.

I have a 2004 cadillac escalade throwing codes po101 and po455. I have replaced the fuel pump, the gas cap, the evap canister, the evap vent valve. Had the system reset and the check engine light is still coming on. What else should I look at replacing? I have reduced power under stress and shuttering when climbing a hill. Its got 126k, should I look at replacing the spark plugs also?

The P0455 code is for EVAP system leak, and a leak problem should not cause an engine performance problems. Now the P0101 code is for the Mass Air Flow (MAF) sensor ( http://www.autocodes.com/p0.... A bad MAF will cause the symptoms you describe. Also, if you have not replace the spark plugs in more 40K-50K miles, is not a bad idea to replace the plugs as well.

Thanks!

I have a 2004 Cadillac CTS with error code P0445 I've replaced the purge valve canister and it's not throwing the code now and the check engine light isn't on now but the engine shutters randomly when at idol now, any ideas? No other codes have came up, please help thanks

Two Thousand Five Cadillac cts evaporation System leaking at idle. The oxygen sensor read a rich rate the and engine had misfire in diferent cilinder

Sounds like the purge solenoid valve is stuck and all the vapors are getting to the engine. The purge solenoid valve is on the engine compartment.

I have 08 cadilac suv. It had a large evap leak. I have it smoke found no leak. I have had everything chage out dealing with this po455 code. Do u think fuel filter might be the cause ? It has a 6.2

No, I have never seen a fuel filter triggering the P0455 code, got to be something else.

I have a 2004 cadillac escalade. We seem to cant get it fixed. First, we replaced the battery & no luck. We had a friend get us a computer and we eventually replaced fuel pump, mass air flow sensor, solenoids, but still will not run. It was idling at one time. We think we are missing something simple. We now come to find the battery (even though we just put in a new one 2 weeks ago) is dead. Any suggestions on where to go from here? Spark plugs were replaced before. cadillac shakes, but will not start. We do have a brand new canister vent solenoid. Where do you suggest we look with a code for a dead battery? What part could say drain a battery if the battery is really dead? Need some advice as I cannot afford a new car for work at this time - running out of ideas -

First of all, the P0455 code is for the EVAP system and that shouldn't cause the no start situation, so forget about the code for now.

So the main problem now is that the engine is not starting?

What is the engine size of your Escalade? 5.3 or 6.0?

Yes the car is not starting. Changed:
Fuel pump
Plugs
Wires
All ignition coils
Maf sensor
Cleaned throttle body
It will not start at all will crank and die out. Extreme engine shaking.
6.0 vortec

Even tough you installed a new fuel pump, I would start by installing a fuel pressure just to make sure there is enough fuel pressure at the time to run the engine. If the fuel pressure is OK, then the next step is to check for spark at the spark plugs.

I have a 06 cadillac escalade esv, have the P0455 code...O'Reilly suggested I replace fuel cap then they cleared the code a week later I got the tighten fuel cap message, check it...went in the house..
When I restarted my vehicle the check engine light came on..auto zone said the code suggested I replace the Evap canister vent valve...is this a difficult repair...is it something a novice can replace??

Yes, you should be able to replace the valve. The valve is attached to the EVAP canister on the back of your vehicle. You have to remove the spare tire to access the valve.

I have a 2008 DTS 4.6 that's showing me the P0455 code. Just changed the fuel cap and still showing the same code. Sometimes I get the slight smell of gas inside my car. Is my tank leaking or is it the evap canister/hose?

It's is difficult to diagnose where the leak is coming from just with the code. The best way is to check under your vehicle and visual check for fuel leaks.

I have 2015 cadillac. I parked the car in parking lot in the cold night, and I turned on the heater long time... then I found the engine light on in the morning(code p0455).I bought a purge valve but I haven’t replaced it yet. Do you think that is good try first?

I would try clearing retighten the gas cap and clear the code first. If the code comes back, the you could replace the purge valve.

I have a 2017 XTS getting the same code. I replaced the purge valve just in case. Still getting the same code. My car does not have a gas cap so I'm not sure what else to check. Any Ideas?

For your vehicle, other than the Purge Valve, the other component that may set the P0455 code is the Vent Solenoid Valve. Since the code is for a "Gross or Large Leak", make sur you check all the hoses going to the canister and the canister itself for damage.

2014 cadillac cts4 2.0 turbo. po455. vehicle does not have gas cap. checked canister found no cracks. changed he solenoid valve. drove for over 150 miles with no issues. filled with gas, light came back on same code. any ideas? no gas smell either.

The Evaporative Emission Canister Purge Solenoid Valve is the most frequent problem on your model year for the P0455 code.

The Evaporative Emission Canister Purge Solenoid Valve is located on top of the engine.