My 2008 HHR SS 5 speed has just over 9k on it, and has been to the dealer twice now for misfiring/loss of boost (because of the misfiring), and it decided to throw the codes again Sunday and Monday. This will be the 3rd time to the dealer to fix it, and all they do is clear the codes, road test and say they couldnt get it to replicate even though the codes are stored.

Anyone else have this issue? I love the car, but due to the lemon law I may have to pick up another one (I will be fighting to get a 2009 this time, or maybe negotiate for a stage upgrade on my current one, as I can clear the codes myself lol).

 

My 07 LT kept throwing P304 codes. The dealer changed a sparkplug in #4 cylinder on one trip. The code would clear itself after 3-4 days and would reappear a few days later. I blamed it on the gas cap. I was late one day and I drove the crap out of it on the way home. 5,500 rpm... really putting my foot in it. The code hasn't been back since.

From what you're saying, you can feel the difference in your's when it is misfiring. I could not tell the difference without the check enginie light. Something on mine must have been clogged and I cleared it out that day.

 

this is a stock SS?

 

yes, it is a completely stock ss. GM has my family blacklisted for other reasons, so the SS is staying stock until the warranty is up LOL.

When it is misfiring, I lose all throttle response, cannot build boost, shutters like mad, then goes away. I still feel it from time to time shuttering, but it doesnt throw the code (this happens on a daily basis), but sunday i could hear it missing and it was throwing codes, but it wasnt shuttering and I still had most of my boost.

 

Took it in Saturday, they looked at it for 2 hours, asked to bring it back Tuesday. They had it all day yesterday, all day today, and just called to tell me they are going to keep it tonight and they will call me late tomorrow morning. So far they have changed the #3 spark plug, that is it. I dont see how that is going to help because the misfire changes between #3 and #4, but whatever. I also told them I can datalog the vehicle when I get it back to pinpoint when/where it happens, but he said that was not necessary (shooting themselves in the foot i think). The last thing he asked (I guess he is a manager of sort), was if he had my permission to drive the car home (20 miles each way) tonight I guess to log it. Anyone heard of such a thing?

 

I'd say hell no, heck I took mine to get a spot on the roof re-painted (under warranty), when I go to pick it up it better not have more then 2 miles more then what was on the odometer when I dropped it off, or there is gonna be hell to pay.

 

2008 HHR SS has a misfiring when driving so why would you tell him to say hell no? you have a paint spot on the roof, I don't think it's the same type repair. If they can't drive it how the H--- can they find what to repair.

 

Cleaning the injectors is where I would start.

 

Okay, so they called me thursday to tell me it was ready for pick up (keep in mind this was the THIRD time, and by florida lemon law the last time for them to try fixing it before starting the lemon law process), I picked it up at 12:00pm Thursday.

I took it easy Friday, had a little fun with it saturday during the day, everything seemed to be good. Saturday night I had to run up to 7-11 at 11:30pm, and it started missing horribly, check engine light flashed 10 times (may have been more but it was at LEAST 10), never before has it ever flashed more than 3 times. I went home, plugged in my HPTuners to scan the codes and it showed; Misfire, Misfire Cylinder 3, Misfire Cylinder 4, Low Voltage.

Now the whole time I have been telling them that the miss jumps, and they have it on file too because the 1st time it was 3, the 2nd time it was 4, and the 3rd time it was back to 3. Why the hell would they change the #3 spark plug when they KNOW from the stored codes that it jumps from 3 to 4?

Also, after reading the codes, I went out to log the car to see if I could pinpoint where and when it misfires. Surprisingly, it seems to miss most often between 1300-2500rpm, low speed, cruising speed it doesnt matter. I also witnessed it misfire on cylinder 1, cylinder 3, cylinder 4, all several times on a 2 mile drive. The odd part is I ran from a stop, launch in 1st, ran up to and shifted at 6500, short shifted into 3rd (6100rpm), I did this 2 times, and it NEVER misfired.

???

It is boggling my mind as to why it would miss at crusing rpm but not at WOT. Also, I noticed a lot of knock, is this normal or is it false knock?

 

Oh, they also did not put gas back in my car after driving it home that night. I dropped it off with almost 3/4 of a tank, and picked it up with 1/4 and the guy telling me "You have a quick little car there, it is hard to grasp how quick they are during test drives, but a 20 mile drive home definitely lets you enjoy it". WTF?