: engine code p0303- anyone had this before ?



thunderbyrd01
04-08-09, 02:19 AM
I have a recent post stating my 05 SRX would "chuggle" (actual word listed on the Tsb's) or hesitate, stutter, etc, usually at highway speeds under a light load. In other words while driving on a flat surface the car is fine but as soon as I have a incline the car starts jumping, chuggling, hesitating around 1500 rpms. while this is happening the engine light would only sometimes come on or flash but as soon as I am back on level ground it goes away and the engine light goed off. I have been told the engine light has to be on to retrieve the codes. Well, after several weeks of this the engine light remains on. The only code showing is "p0303" misfire cylinder 3. Has anyone else ever experienced this ? How was it repaired ? Any information would be helpful. Thanks everyone:

n7don_srx
04-08-09, 10:50 AM
I have been told the engine light has to be on to retrieve the codes. Well, after several weeks of this the engine light remains on. The only code showing is "p0303" misfire cylinder 3. Has anyone else ever experienced this ? How was it repaired ? Any information would be helpful. Thanks everyone:

Actually if a code has been set it will be stored and can be retrieved from the pcm's history. The light doesn't have to be on. If the malfunction that caused the code to be set doesn't reoccured, the history is erased. Not sure of how our pcm is programmed but on some GM vehicles it was like 40 restarts.
Misfires can be caused by a number of things so I can only offer some generic things to try. If you've not be using a toptier gas, the injector may be dirty. Try a adding some Chevron Tectron injector cleaner to the next fillup. Some people also like SeaFoam and add some to the gas and suck some thru the brake booster vacuum line. Be aware the later will cause the fire dept to respond to the smoke!!
I think our engines use a coil-on-plug. In other words each cylinder has it's own spark coil that sets on top of the spark plug. If #3 is going bad that plug won't fire properly. I don't have any experience with this but on my 03 Envoy it's fairly easy to swap the coils to another cylinder and see if the misfire follows the coil. I've read in other posting that some have had problems with these coils but don't know if they can individually be swapped around.
If you do get to point of checking the #3 coil it's probably easy to also make sure the spark plug isn't fowled. How many miles do you have? My experience has been plugs will last 100,000 miles but there are exceptions.
Out of curosity, do you have an aftermarket alarm system installed? Those systems that interupt the ignitions system have been known to cause misfires.
Let us know what you find and hope you have success fixing the problem.

thunderbyrd01
04-08-09, 11:53 AM
Thanks for your input. To answer a couple of questions; it has 84k pampered miles & always garaged, I've been accused by several as having OCD about my SRX. It has no after market alarm though. Just doing general research online the coils are mentioned more than the plugs, wires, and injectors. Thanks again and I will post my results as I go so others can benefit.