P0303 Cylinder 3 Misfire
 

P0303 Cylinder 3 Misfire

Can someone explain this to me? I have it along with:

P0171

P0303 means you have a misfire condition on cylinder #3, it can be caused by a bad spark plug, bad injector, or in the worst case scenario....a blown head gasket/cracked head.

Give this thread a read.....

https://www.chevyhhr.net/forums/problems-service-repairs-42/cel-fuel-injector-18749/

This requires some diagnostic work like a compression test, a check of the spark plugs and replacement of them if needed(if you're close to the recommended mileage for replacement, might as well do them), checking the oil for coolant contamination, etc.

Both together point to a bad injector.

Oh no :pullinghair:
How long would you think the code would pop back up if it was something with the 3rd cylinder?

I reset the light 24 hours ago and the only code I have so far is P0171, P0303 has not came back yet and I have driven a good 40 miles since I reset it.

That depends on whether it was a spurious fault triggered by the original P0171, or whether its another fault unrelated to(but coincidental to)the P0171 that keeps coming back.

Keep an eye on it, once you've attended to the first fault code, it may not come back.

my 2007 2lt with 2.4l had similar code.
dealer had to replace all 4 injectors(under powertrain warranty)
something about a matched set of 4???
not sure if that's correct ,but as it was warranty i did not argue

Did their repair take care of what you were experiencing with your HHR?

Michelle, Chevrolet Customer Service

I later figured out that P303 code was set due to very low gas. I was driving around trying to get the gas to low so that I could replace the fuel pump.

Hello
 

I know that it has been a while since I posted this thread but I want to apologize for not following up on it. I Thank everyone for their replies. Have a blessed day. Stay safe and healthy.

You haven't posted in this thread before. What are you trying to update? You should find the thread that you want to update, and give whatever information you want to pass along.