1. The vehicle came with a muffler on it, it was removed and replaced with a piece of 2.5" pipe.

2. The muffler was replaced by a 30+ year ASE mechanic, who I trust a whole lot more than some ass-jack at the dealership, and his race cars dont lie either.

3. As far as the backpressure thing goes, I call hogwash. I was running dual 3" completely straight exhaust into flowmaster 30's and turndowns on my 95 s10, and it ran the exact same time with the exhaust on it, as it did with open longtubes. Same thing, my brother's LS1 camaro ran the exact same time with his open longtubes as it did with the full y-pipe and cat back (flowmaster again). Some motors like backpressure, some dont care as long as the exhaust is free flowing out and not trying to get sucked back into the exhaust side of the motor.

4. I did some looking on exhaust warranties, of course on the interwebZ, and could come across nothing regarding the exhaust being warrantied, only how they are not warrantied. Which I agree with, due to the exhaust not being coated at all. Also, since I contacted bob steele before doing so, they told me that there would be no warranty voided, and recommended leaving the cat and resonator in place just in case. Had the dealership (or the tech that flew down from detroit this last visit to the dealer), had any problems with the muffler being removed, I am fairly certain that they would have said something since I have no problem welding it back into place.

5. Stage 1 power program? I am unsure as to what that is. I would love to be able to lean it out, but GM's warranty wont allow me to. If it was out of warranty, I would just fix it myself. But, since the dealership turned down my offer to datalog the vehicle to pinpoint exactly when the misfires happen, I have since stopped trying to help them. HPTuners tells a lot about a vehicle, but GM knows when an ECU has been overwritten.

6. No other mods have been made to the car, even though I would love to upgrade the intercooler piping and maybe a short shifter. The biggest thing I would like to be able to do though is tune it.

7. Maybe they should try swapping the coils? you know, something that is completely and directly related to firing the spark plugs? To my knowledge, they havent even tested the coils, or if they have, they havent made a note of it on any paperwork. Since, up to date, they have informed me of any changes or things they have tried, right down to changing the #4 spark plug (even though it was cylinder 1, 3 and 4 that were misfiring) the first time it came to the dealer.

Picked the car up thursday at 5:20pm. Drove it a bit that night, felt it miss a couple times while cruising. Friday same thing, today I felt it miss 1 large time (that whole motor jerking thing I mentioned before) but no codes so far. Wife has the vehicle so I cant check atm.

If anyone else has any questions, please let me know.

 

Do you still have the factory muffler? If so, put it back and prove that the problem still exists. Until you do that they can continue to point the finger at the change you made. If you don't want to listen to some of the other knowledgable members, then do whatever you want and see how it turns out for you.

 

who pointing the finger? The dealership isnt pointing towards the muffler being a problem whatsoever, with anything.

 

That's wonderful that you have such a good relationship with this mechanic. Chevrolet, however, may not have the same inherent trust in your buddy, over their thousands of design engineers.

Wrt this mechanic's race cars and his ability to install a straight pipe in place of a muffler... well, I'm not even going to try to figure out what this is supposed to mean to us.

As proof of this revelation, you offer butt-dyno evidence from yours and your brother's cars?

And so the zillion dollar performance aftermarket exhaust component industry is all just BS? All these exhaust system products-- headers, "high performance" CATs, H-pipes, Y-pipes, X-pipes, and the 150 different muffler designs out there don't do ANYTHING to the engine's operation? Nothing? Methinks you've been sniffing that tailpipe again.


The exhaust is part of GM's 100k mile bumper-to-bumper warranty. In addition, I believe it is also covered by a separate emissions system warranty (they may have rolled that into the b-to-b). It is also covered by Fed regs and most state's laws. Removing or modifying the factory CAT is a violation of Fed regs. Even swapping out the CAT for another type/model/brand _may_ be a violation of Fed regs and/or some state laws.

This item really needs to go last, as it sums things up. You modified the drivetrain component, and now you are calling the car a lemon. Whether there was any impact to this change is almost irrelevant... you "broke the seal" on the system and now you want them to take it back. Sorry... you broke the seal. Have fun arguing your case. Based on the information in this thread, you don't deserve compensation until your right the car and prove that the problem still exists.

 

If they haven't yet, they will point the finger at the modification soon. Change it back until you get this resolved. It doesn't really matter if you're right or wrong; you will have a much better chance to prove your case if you put it back to "factory" and show that the problem is still there. There is simply no way around it.

 

Im done arguing it, there seems to be no point to it. Apparently I know nothing of vehicles, not to even start talking about higher performance vehicles. Maybe the LS3 we driveway swapped into our 2005 GTO isnt good enough? Or the LQ4/4L60E into our 98 Jimmy? My 94 GMC with a 2002 5.3/4L60E? X pipes and high flow cats? What the hell are those???

Regardless, I will keep you posted on the car.

 

All that is irrelevant. You're in the process of filing a lemon claim so you have to think of your situation. If I'm on the jury hearing your case I'm sitting here wondering what else Mr. McTinkerson has done to mess his car up. Not looking good for you.

You're really not helping your case talking about race cars and whatnot, because that's not what GM sold you. Probably best not to mention any of that in an official setting.

 

Twice in one thread. You are a master!

 

Intermittent misfires are the worst kind to diagnose because the misfire comes and goes depending on engine load or operating conditions. The engine may only misfire and run rough when cold but then smooth out as it warms up. Or, it may start and idle fine but then misfires or hesitates when it comes under load. Also, it may run fine most of the time but suddenly misfires or cuts out for no apparent reason. Intermittent misfires can be a real challenge to diagnose.

Beyond the timing, coils, spark plugs, injectors and valves - intermittent low fuel pressure can also starve the engine for fuel and create a lean fuel mixture that can cause misfires.

As stated in a prior post - why not take the HHR to another GM Dealer e.g. -
Rosner Chevrolet
800 S. Harbor City Blvd.
Melbourne, Florida

 

I work in the performace aftermarket and see people do a lot of things. Todays cars are not just a simple bolt on in all cases. Some small changes can really mess things up and were done by people with a ASE rating.

I one has a ASE guy [a GM trained dealer tech] Argue we sent him the wrong crank. It was hitting the block and the block needed clearanced. It took me a while till I could convince him that building a stocker engine that he was inceasing the stroke and needed a special pan and clearanced block. Once he understood we were fine. He just did not know. THese things are not on the ASE test.

I also see good mechanics every day wipe out cam because they do no know about the lack of Zinc in the oil today. It was reoved about a year ago and is needed for breakin.

There are many things most good mechanical people just don't know because no one knows it all.

The 2.0 is a very complex engine that most dealer struggle with and even here the guys making mods are often learning the hard way.

The bottom line is GM can and will kill a warrantry when you start to make changes. Often they have no way to know if or if not some of these changes have mess someting up. Even GM after spending million on some of these engine learn after production starts things that need fixed like the low vac on the turbo engine at start up.

GM has to protect themselves with the warranty. Often they are expected to pay of fix someone elses error. People can and should be able to make mods but also need to be prepared to accpet the responsibility that goes with it. If you can not afford or are willing to accept this then don't mess with it till the warranrty is out.

I feel for you and I am sure it will get worked out but don't expect GM to buy back a car with mods.

Also note to all GM people here do read on this site so I would not brag too much about racing and other behavior that would result in the eliminatation of a warranty claim. The Subaru WRX guys have already had issues for Racing and Subaru has found their post to use against them.

In racing you play you pay no one raced free.