Check Gas Cap & Engine Light

buick
lacrosse

#1

2006 Buick Lacrosse, CXL, 78K miles. 6 months ago, the check gas cap message came on. The gas cap was replaced. The message is still on. Soon after, the engine light came on as well. The Buick dealer said (without running a diagnostic or looking at the car) we needed to replace the catalytic converter and it would be expensive! Had 2 diagnostic tests run - one at a garage and one at an auto parts shop. No codes were detected.

Whenever the car is close to its 3k oil change, an “'oil low” message appears. The oil has never been low, it’s an annoying message to get the oil changed. As the gas cap/engine light came on shortly before its 75K mile check, could this be the same case?

The car runs great and there has been no change in gas mileage.

Can anyone help?

DollarBill


#2

If the check engine light is on, there are codes. The codes may have to be retrieved by the dealer though as the parts store and the garage you used my be using a generic code reader and it can only read generic codes.

You will need to pay for diagnostics though at the dealership, and it will be worth every penny. If done properly, they will hookup a scanner specific for GM vehicles and they will not only retrieve the code(s), but will follow the diagnostic charts to isolate right down the the specific component that is the root cause.

If the service writer at the dealership says that you don’t need the diagnostics and that you absolutely need a new cat, then ask him if he will personally refund 100% of your money when the cat doesn’t fix the problem. Remind him that if the check engine light comes on within two drive cycles of leaving the shop, it was not fixed.


#3

The catalytic converter on your vehicle is warranted for 8 years/80,000 miles. So if there is indeed a problem with the catalytic converter the dealer must replace it for free.

Any independent shop with a true scanner can retreive any DTC’s from your vehicle.

Tester


#4

Not 100% certain, but I think it used to be the case at least in Calif the cat and all other emissions parts must be warrantied for 100K. If no codes could be found, it may be the battery was disconnected. That can sometimes erase the codes. But if the problem remains, in a week or two they will come back. It sounds like you aren’t entirely pleased with this dealer shop. No harm done to ask an inde shop to offer an assessment. Yours isn’t the only car to have the check engine light come on. You might end up money ahead.


#5

The EPA/CARB warranty on computers and catalytic converters is 8 years/80,000 miles.

On all other emission control devices it’s 2 years/24,000 miles.

It’s been this way since OBDII or1996.

Tester


#6

@dollarbill

check gas cap message = you need a cat

I suspect whoever said that is short on automotive knowledge

IMO . . . you may need an evap purge valve . . . not uncommon on GM vehicles

You probably have a P0442 evap code, or a very similar code


#7

rember not all service writers are mechcanics at one time they are sales people paid buy what they can sale you. there are some good ones out there that don,t try to sell you everthing under the sun


#8

But selling an unnecessary cat is just bad business

The customer will be upset when the check gas cap message comes back on

The customer might angrily storm into the manager’s office

The customer might tell their friends, neighbors, etc. about the bad experience they had

Some of those people that hear about it may stop bringing their car to that shop


#9
But selling an unnecessary cat is just bad business

The customer will be upset when the check gas cap message comes back on

Not at all…The sleazy mechanic…will charge the customer for a new cat…but just put on a new gas cap. Problem fixed…customer is happy…and the sleazy mechanic is VERY HAPPY.


#10

@MikeInNH

We’re not all like that

Unfortunately, the bad apples spoil the barrel

Or to put it another way, the sleazy mechanics give the industry a bad name

I might add, however, that it’s often the shop owners who “encourage” the mechanics to engage in dishonest/fraudulent behavior

I suppose a mechanic in that type of environment is always free to look for a more honest employer


#11
We're not all like that

Unfortunately, the bad apples spoil the barrel

Or to put it another way, the sleazy mechanics give the industry a bad name

I might add, however, that it’s often the shop owners who “encourage” the mechanics to engage in dishonest/fraudulent behavior

And I wasn’t implying that you were…or any of the mechanics in this forum are.

I have 3 different shops I go to for work on cars. One place for tires…One is a transmission specialist…and he does all my tranny fluid changes…and the other is for general repairs that I don’t want to do or have the time or equipment for. And they are all small shops with 3-4 people…very honest and trustworthy.


#12

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.