I am getting codes P0442 and P0507.
I looked up each code and this what they mean:
P0442 Evaporative Emission Control System Leak Detected (small leak)
This indicates a fuel vapor leak in the EVAP control system. It means a very small leak has been detected. In fact, the leak can be from a hole as small as 0.04" in diameter. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.
A code P0442 most likely means one or more of the following has happened:
A loose or improperly affixed gas cap
A non-conforming gas cap (i.e. not factory/original brand)
A small leak/hole in a fuel vapor hose/tube
Other small leak in EVAP system
Faulty vent o-ring seal
I have not done much yet with this code, I am planning on replacing the gas cap to see. But I do smell gas outside of the car after running the car, dont smell gas inside the car, only outside. The engine light dont throw this code til i get down to about 1/4 tank of gas, then if i reset light and fill up it stays off til i get down to about a 1/4 again.
P0507 Idle Air Control (IAC) System RPM Higher Than Expected
This P0507 code is one that's sometimes triggered on vehicles that have electronic throttle control. That is, they don't have a regular throttle cable from the accelerator pedal to the engine. They rely on sensors and electronics to control the throttle. In this case, the P0507 DTC (diagnostic trouble code) is triggered when the PCM (powertrain control module) detects an engine idle speed that is greater than the desired (pre-programmed) RPM. In the case of GM vehicles (and possibly others) if the idle speed is over 200 rpm higher than expected, this code will be set.
A P0507 DTC trouble code may be caused by one or more of the following:
A vacuum leak
Leaking air intake after the throttle body
EGR valve leaking vacuum
A faulty positive crankcase ventilation (PCV) valve
Damaged/failed/dirty throttle body
Failed EVAP system
Failed IAC (idle air controller) or faulty IAC circuit
I have done replaced the PCV and IAC valve's (I did check the IAC Pintle distance and did the IAC reset). I reset the engine light and it stays off for about 500 miles, then comes back on. I noticed it takes a bit of holding the key to start the car and it idles around 1200 rpm all the time, cold or hot. I do not hear any vacuum leaks and I have sprayed the entire engine bay down tryin to find a vacuum leak and absolutely nothing found so far. Also the entire intake system (upper and lower manifolds and TB) were all cleaned when motor was rebuilt.
Edited by joesperformance, 24 March 2011 - 11:58 AM.