I have 3 codes on my 08 impala; P0455 P0521 P1174 not really sure where to even start. I need to pass my emissions test so I can get new plate stickers. I do not have enough money to take this to a mechanic, so I am trying to fix this myself. Any suggestions?
The 455 and 1174 are probably related to the same issue---emissions and air to fuel mixture which could be a purge valve for the evap. system and the 521 is usually a bad oil pressure sensor.
SOURCE: p0455 comes back on ,we try to fix it
The EVAP control sytem is checked by the ECM upon the first start of the day when the engine is cool and will trigger the DTC code P0445. If you have a vacuum line leak when it's cold and seals it self when it warms up then the code will stay there. After warming up the car reset the ECM to clear any DTC codes and see if any MILL shows up. IF not then there is a leak only when the system is cold so your going to have to try to do a smoke test when the system is cold.
The other thing is to check all the vacuum lines and fittings around the canister and fuel tank for any lose clamps ECT.
Good luck and keep me posted. Be glad to help you
SOURCE: Code Scan Reads P0455 Evap. Emissions Leak, Large
large leek is usually the gas cap. just had the same problem
SOURCE: What is code P0455- Emissions leak
well you can have o'reillys use the scan tool to clear codes in the computer and the light will go out unless the problem still exists then it will come back on. this code means that maybe something is wrong in the evap system. i have a question for youl. when you get gas do you stop when filling up and the pump kicks off the first time or do you kepp filling a little more each time trying to top it off better. what many people do not know is that you can do this but it is filling the lines of the evap system with gasoline which will eventually cause problems with the system. the evap controls fuel vapors from the gas tank and it can not work if it is full of gas. i am sure you understand gasoline turns to vapor quickly. gas in your gas tank does too. to keep it under control the evap system gathers it and purges it with switches and sensors that can be damaged by liquid gas. so can vacuum lines. they will swell and leak and all of these will cause the system to fail and the computer will set a code and the light comes on. also the gas cap being lose while the engine is running will do the same.if that is the problem you will need a skilled tech to figure out what is wrong and replace it. if your getting gas always stop the first time the pump kicks off. hope this helps and good luck
SOURCE: 08 Impala - Check engine lite on - Large Evap leak detected
If it is missing or not running perfectly you can damage the Oxygen sensors or the catalytic converter. If it is running perfectly then more than likely no damage will be done, but you still need to have it looked at by a professional with the proper tools and skill to diagnosis the problem and not just throw parts at it. The PCM and catalytic converter are covered by an 8 year 80,000 mile warranty whichever comes first. To know if your defect is covered which is highly unlikely, you need to talk to your local GM dealer.
Testimonial: "Appreciate the help. It really was helpful."
1,045 views
Usually answered in minutes!
×