2001 grand am engine light

[robertpelley]

I have a 2001 grand am 2.4L that has the "SERVICE ENGINE SOON" light and the "TRAC OFF" light on and is idling rough. The code read "MISFIRE ON CYLINDER #2" so I changed the coil and no change. what should i do?

[goodoldpapa]

I presume the code was P0302. Have the spark plugs and boot covers been changed as well? Worst case scenario would related to the fuel injector. Maybe this might help http://www.obd-codes.com/p0302. I have heard that when the trac off light comes on that it could be wheel bearing related, but usually the ABS light and/or SVS lights are on as well. Haven't had that problem, but some of the others with more knowledge would be better able to narrow it down than me. hope this helps.

[3100]

track off light - can come on if you hit the switch on the shifter lever

- remove spark plug for the #2 cyl look for coolant or oil on the plug, if the spark plug is dry and clean then
- ohm all the injectors if No. 2 is odd ball replace it (most likely injector is shorted or clogged)

[robertpelley]

thanks goodoldpapa, And yes I changed the plugs and the boot covers still the same.

[robertpelley]

how do I ohm the injectors?

[goodoldpapa]

Someone correct me if I'm wrong but I believe you have to use what is called a noid light to check the ohms on the injectors.

[robertpelley]

ok i have ohm the injectors and all is between 13.2 and 13.4 ohms so i am guessing they are all ok, I pulled all the spark plugs all seems to be ok there as well, anymore suggestions? what could it be?

[xeroinfinity]

[quote=goodoldpapaSomeone correct me if I'm wrong but I believe you have to use what is called a noid light to check the ohms on the injectors. [/QUOTE]
You would use a noid to see if the injector is getting pulse signal from the PCM.
To read the ohms, you need a multimeter. You just measure acrossed the injector terminals.

My guess would be coil(s) or ICM causing the misfire.

Also the low trac light does flicker off and on, especialy if you break traction at any speed. If it stays on and or your abs/trac off light stays on, those need scanned with an ABS capable scan tool.