Rough Idle, Exaust Tone Change, Sensors.. [Archive] - GrandAmGT.com Forum

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Dmac8323
02-14-2013, 11:38 AM
Hello, I'll just start off with that I have a 2004 Pontiac Grand AM GT..

The issue I am having is a Flashing SES light when driving down the road and very great loss of power and my exhaust changes tones from its proper "loud" sound to a quieter sound. When the car is idling the car is "shaking" a bit. These issues used to only occur once every 4 months, now its happening quite often.


I took the car to Advanced and got the codes ran and it came as a Mass Air Flow Sensor problem as well with one of the O2 senors.

They suggested cleaning the MAF sensor and changing the Air Filter to see if that clears up the issues and it has not. The problems are still occurring. So I'm not sure if I need to replace it or not.

I am planning on also changing spark plugs and fuel filter seeing that they probably have not been changed on this vehicle yet.

If anyone has had similar issues or suggestions on what it could be and how to fix it, all input would be greatly appreciated. Especially seeing that I have little Grand Am repair experience. Thanks!

sleepyalero
02-14-2013, 12:24 PM
Interesting a flashing light usually means really bad...

Replace maf, replace o2 see what happens.

AaronGTR
02-14-2013, 03:39 PM
Flashing SES light is very bad! Stop driving the car or get it fixed as soon as possible!

A flashing SES is the indicator for a major misfire, that has the potential to damage the catalytic converter. If you've cleaned the MAF and replaced the air filter already, but are still getting a MAF code, then the MAF sensor is probably bad and needs to be replaced. It does happen occasionally on high mileage cars.

How many miles are on your car? A lot of people neglect the regularly scheduled maintenance on cars and that can lead to a lot of the issues you are having. Spark plugs and O2 sensors are only good to around 100,000 miles. If you are over that and they've never been replaced, then they need to be changed. Also fuel filters should be changed every 30,000 miles, and low fuel pressure could also lead to a misfire so that might need to be changed as well. Coolant is only good for 5 years/60,000 miles, trans fluid and filter 100k miles, brakes should be bleed and fresh fluid added every 3 years. Keeping up with this stuff will help the cars systems last longer without needing major repairs.



It sounds to me like you need a full tune up now. New plugs and wires, MAF sensor and O2 sensors, fuel filter. Try those and see if the problem goes away. Might want to run some fuel system cleaner through the tank after changing the fuel filter also to help clean the injectors. If that doesn't solve the problem, another thing you can check for is a clogged catalytic converter. They don't last forever, and a clogged cat will also cause all the symptoms you mentioned, although it would be more of a continual problem and not something that comes and goes.

kzulfic
02-14-2013, 04:36 PM
I had this same problem. Same symptoms, rough idle flashing SES light etc. It also occurred intermittently, turned out it was a broken wire inside the MAF sensor plug.

One thing that you didn't mention that I experienced was hard shifting which can occur from MAF problems. Have you had any hard shifting or slamming into park and reverse?

Dmac8323
02-15-2013, 08:51 AM
Well I took it to the a garage. Cylinders 2 and 5 were dead (Causing the Misfire) and with the computer we could see that the MAF Sensor was functioning properly. However the one O2 sensor dealing with those 2 "dead Cylinders" was not responding. I was suggested to change all spark plugs and wires to get rid of the dead Cylinders and then he would be able to determine if the O2 sensor is bad. Thanks for your reply's guys. Greatly Appreciate it.