I have a 2006 LT w/89,000 miles. Was purring like a kitten until a fuel fill up and a drive through terrible storms. The HHR started misfiring and the check engine light came on. Symptoms were intermittent, but have increased and stalls a lot and check engine light blinks. Checked w/code reader and it just said: random misfire… clean fuel injectors. Put cleaner in 2 fill ups, but no change. Took it to my mechanic who said I needed a new MAP sensor. Changed sensor and spark plugs, but still have the same problem. It also sounds like I have a small exhaust leak, so mechanic checked and said there’s a slight crack in the flex pipe coming off the manifold. Also, he suggests now that all arrows point to bad fuel injector seals (he says there’s raw fuel in couple of cylinders).
Wondering what you all think… before I spend even more money.

 

Fix the flex pipe. Do not drive until you do so. It's ruining your catalyst.

 

Welcome
You should post up the actual codes #’s. Description of codes can vary from one reader to another. Sometimes those descriptions can be wrong and lead you in the wrong direction.
So. Code #’s only if you’re asking for help.

Also. Which engine ? 2.2 or 2.4.

 

It is NOT "random misfires: It IS "misfire detected". Misfires are detected by noticing a variation in the crankshaft RPM compared to the valve timing.
If there was "raw fuel in a couple of cylinders" There would be more codes than P0300. ?Your mechanic is spewing.
Which engine is this? 2.2L or 2.4L, the 2.4L would have "VVT" on the valve cover.
I see absolutely NO indication of any injector problems, from facts presented.
If the CEL is flashing it means to PARK the CAR, either the catalytic converter is clogged or it will be soon.

 

One and Done.