Mechanics

CHEVY ENGINE LIGHT ON

2006 Chevrolet Impala

Engine Mechanical problem
2006 Chevy Impala 6 cyl Front Wheel Drive Automatic 78000 miles

My Engine light is ON, got it checked by a Computer Code machine, they say not a major problem but something to do with Gas Evap or temp change.
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Baxa
April 7, 2010.



Do you have the trouble code? So I can look it up

The Code is 496

Tiny
Baxa
Apr 7, 2010.
Thats strange, I dont have that code in my refferences, are you positive?

Yes, the code in my invoice mentioned by the garage is
po496 EVAP SYSTEM FLOW DURING NON PURGE,
MANIFOLD FLOW TO THE EVAP SYSTEM
HAD UNDESIRED INTAKE
BARO PRESSURE ABOVE 74 KPA
GAS CAP NOT CLOSING PROPERLY
POSSIBLE PRESSURE LEAK

I hope that suffice, can you please help on the matter?

Tiny
Baxa
Apr 7, 2010.
Ok, let me ask you this, when you close your gas cap, do you keep turning it until it click, click, clicks, or do you just turn it until it stops?

Also I need you to check/change the mapp sensor

Your question about the Gas Cap,
Yes I try to close the Gas Cap I turn until it gives the Click, click sound - maybe 2 times, but it should be turned how many times is not clear as the Gas Cap can be turned even after 2 turns clockwise, so I normally stop turning to avoid breaking the cap.

About the Map Sensor - Please guide me how and what to check and report back to you.
Your help is highly appreciated.

Tiny
Baxa
Apr 7, 2010.
It wont break so a few clicks is fine, but you may have to replace it, it might not be holding pressure. The mapp sensor is located at the back of the intake manifold, usually like right in the middle, it has a little diaphram on the inside, check the vacuum hose going to it for cracks or it being flat and dilapidated. Also, you can probably unhook it and see if you can blow, compressed air through it and clear it of any dirt oil/debris. If its caked up with dirt/oil then just replace it and then change the pcv valve too, because that is the reason why its caked up, is because the engine isnt venting properly