GM CORPORATE CANT EVEN FIX MY CAR

[MrChrisLS3]

Whatever the case, I know if it were me, I would first take the car to a performance shop that is more likely to have some experience in dealing with cars with cat deletes and such. Especially given the circumstance of doing the mod and trouble immediately begins. Trying to get a warranty diagnosis on a modification caused problem is barking up the wrong tree. even if he did tell them up front what he did, they still couldn't do anything about it.

I'd be willing to bet the service guys have a pretty good idea of what the problem is. I mean, there's no way that you remove all material from the cats and the car not sound significantly different. Add that you're talking about a bunch of people that turn wrenches for living, do you really think none of them are enthusiasts that more than familiar with this type of thing? I highly doubt it. I'd also be willing to bet that, for his symptoms, the diagnosis trouble shooting guide points in this direction, if not first, very close to the top. I wonder if "not being able to figure it out" is the dealerships nice way of saying "we're not touching this with ten foot pole". Given that they have a customer that has illegally modified a Federally mandated emission system. I'm not sure what their protocol would be if they "officially" addressed it, perhaps it would get the owner in some very hot water.

The OP is standing at that turning point called "Go big, or go home". It's either replace the factory cats and ride out the warranty term, or tune the car and kiss the powertrain warranty good bye.

The OP has seven threads discussing this issue, plenty of "I told you so" in all of those.

[cb66]

Originally Posted by Avenging Orange

Another case of people modifying their vehicle and expecting the manufacturer to fix their mistakes......for free.

You hit the nail right on the head !!!

[jeff657756]

Good luck to the OP. It honestly sounds like the car hasn't ran right since the cats were gutted. If so, then something happened during that "process". There is no such thing as a coincidence.

[Jazzzed]

Originally Posted by MrChrisLS3

The OP is standing at that turning point called "Go big, or go home". It's either replace the factory cats and ride out the warranty term, or tune the car and kiss the powertrain warranty good bye.

I have a 2015, and I tuned and kissed. 😛

[GVA 45TH 2SS]

Pretty simple.
Pre and post CAT O2s reading the same because the CAT was gutted.
There is a trick to make the downstream sensor read a lower temp making the ECM think the CAT is doing its job. But the car is constantly adjusting A/F ratio trying to compensate.
Best way is a tune though, and since you refused to do it here you are.

As someone pointed out earlier- the car is in open loop when cold.
All that aside, eventually a good tech is going to see the readings and pull off the CATs and see what has been done. At that point I would think the OP will get a large bill for Labor and replacement of the CATs, O2s and anything else they change while trying to diagnose the problem.
Not to mention GM customer service has probably seen this thread.

[Irace16]

Originally Posted by Irace16

Sounds like a buy back to me... After three attempts to repair the same problem or 30days in the shop I believe are the lemon law rules

After reading this thread, disregard what I said lol

[Jfoster]

Originally Posted by MrChrisLS3

Whatever the case, I know if it were me, I would first take the car to a performance shop that is more likely to have some experience in dealing with cars with cat deletes and such. Especially given the circumstance of doing the mod and trouble immediately begins. Trying to get a warranty diagnosis on a modification caused problem is barking up the wrong tree. even if he did tell them up front what he did, they still couldn't do anything about it.

I'd be willing to bet the service guys have a pretty good idea of what the problem is. I mean, there's no way that you remove all material from the cats and the car not sound significantly different. Add that you're talking about a bunch of people that turn wrenches for living, do you really think none of them are enthusiasts that more than familiar with this type of thing? I highly doubt it. I'd also be willing to bet that, for his symptoms, the diagnosis trouble shooting guide points in this direction, if not first, very close to the top. I wonder if "not being able to figure it out" is the dealerships nice way of saying "we're not touching this with ten foot pole". Given that they have a customer that has illegally modified a Federally mandated emission system. I'm not sure what their protocol would be if they "officially" addressed it, perhaps it would get the owner in some very hot water.

The OP is standing at that turning point called "Go big, or go home". It's either replace the factory cats and ride out the warranty term, or tune the car and kiss the powertrain warranty good bye.

The OP has seven threads discussing this issue, plenty of "I told you so" in all of those.

Not to mention they all smelled it when they drove it in the shop.

[daveyio87]

I bet the exhaust doesn't have enough back pressure with the gutted cats. People who modify their car have it tuned. when i put my headers on the car ran fine a whole season before throwing a check engine light, got it tuned the next spring, the car runs even better.

The reason i talk about back pressure is because i had a 2013 2.5 Malibu i was cleaning carbon out of the head for a secondary air issue and wanted to crank the engine over to blow any deposits right out of the head before putting the manifold on, with the manifold on and the engine cranking it sounded like the engine was dead and had no compression and cranked a lot slower...

Just put some quality aftermarket parts on it and get it tuned and be done with it. I hate people who modify their cars and bring it do the dealer with drive ability issues, and the issue could be resolved with a tune for compensating for more air intake to the engine or a modified exhaust. The reason GM hasn't seen anything like that before is because one of the first questions they ask when calling for technical help is any aftermarket items on the vehicle and depending what it is they ask you to remove them before going any further with diagnosing.

[maddoggyusa]

Originally Posted by JLSuperfly

Agreed. That is like going to the ER and doctors can't figure out what is wrong with you because you withheld the fact that you had sex with the outbreak monkey the day before.

OMG too funny

[Ashen L99]

Any news OP?

[Ace0751]

Haven't heard from the op in a while, what gives.

[MrChrisLS3]

Originally Posted by Ace0751

Haven't heard from the op in a while, what gives.

Pretty simple really, instead of us jumping on bash GM bandwagon, we pointed out that he caused his own problems.

[JLSuperfly]

I am also curious as to what happened next. OP, can you update us?

[Spec]

Originally Posted by JLSuperfly

Agreed. That is like going to the ER and doctors can't figure out what is wrong with you because you withheld the fact that you had sex with the outbreak monkey the day before.

Haha.