Hello all and good day. I've got a 2008 SE 2.2 non vvt 140,000 miles. Keep getting a misfire cylinder 2 and haven't been able to track it down. I've replaced coils, plugs, and injectors. All in which I replaced with oem replacements. Ran compression tester and all cylinders are running 160 +- 5%. It's running like crap but when you get on it it'll straighten up so I ran real time diagnostics and it shows fuel system open loop fail until you get in it hard. Than it goes to closed loop and runs fine. I unplugged maf sensor and it's running better but I'm looking for something I've over looked. Thanks in advanced for any suggestions.

 

Is this an HHR ? Because no such thing as a SE. HHR ‘s were LS, 1LT, 2LT or SS models.

 

Welcome to the site, SE might mean Special Edition or Spring Edition, it’s the engine that is the concern.
so to clarify you don’t mention a MIL or CEL code. Most likely P0302, which can be caused by low fuel pressure also , it should be around 55 to 60 PSI and not dropping off after you turn the key off.
It can also be loose or bent pin in the coil or injector electrical connections

 

It's a 2008 Chevrolet HHR Special Edition 2LT. Being a HHR site i figured people would know SE stood for Special Edition....my bad.

 

Thank you. I'll check pressure and see what it's running and see if it leaks off quick or not. Thank you for replying

 

You’re welcome, and I did see the code in the title.

 

Actually, there were Spring, Fall, Premiere and Shadow editions. I’ve never heard of a Special Edition except, one that a member here created. ( he got an emblem off of EBay, stuck it on his black 2008 and called it a Special Edition )

 

Mine has Special Edition badge and I can assure you it's not from ebay. It was called Special Edition by dealer when I purchased it new, you can google it and same car I own comes up so I'll go with Special Edition. I'm more into older cars but got HHR for daily as it has a retro look.

 

Slow to closed loop might be an O2 sensor issue but should throw a code. That should not affect just cylinder #2 tho. No other codes?

You could try cleaning the MAF sensor and throttle body. You might also look for a gasket leak where the intake manifold hits #2.

 

P0302 would keep open loop.