my car recently just started to struggle when accelerating and kept shutting off. sometimes i would floor it and it would only go like 20 mph, and then it would go back to normal. then it died on me and took me a while to get it started back up again. i got it to autozone fine and they read the codes and told me that it was a problem with my cat. today it accelerated fine but in about 5 miles of driving the car shut off on me 4 times. ive also been getting really bad gas mileage like 15 mpg. would a problem with the cat cause the car to shut off, not accelerate right, and get such horrible gas mileage? whether it can or not, could someone tell me what i should have fixed or what i should do and how much it will cost me. thanks

 

could easily be cat failure- they plug up- or the stuff inside getrs loose and when you start driving it blocks the exhaust flow and stalls the engine
It is not safe to drive this way!!!
If you have ramps or a floor jack NOT the wimpy car jack- raise the car0 support with jackstands if on a jack- then pound on the cat with your fist or a rubber mallet- not a real hammer- you are listening for loose materials
A muffler shop can replace it for you-
BUT
depending on your miles/year, it may still be covered on the special emission equipment warranty- something caused it to fail- they normally have a long and happy life-
lots of high rpm, hi speeds can cause problems-
Whats your miles now

 

around 150k

 

get a RT Cat for like $300 or less shipped instead of the OEM $800.00 one. The RT Cat will give you a little better top end accelerations. I changed mine out at 162k and it made a very nice difference.

 

150k miles- ok thats a bit past the 80k mile warranty extension- so its still time to have a muffler shop inspect it and confirm thats the problem
That would be normal mileage for a wear out failure- not anything you did.

See what they have at the muffler shop for proper cat for the TL, when you get into the hi flow ones- there may be need for a spacer on the 02 sensor- or I may have my modifications crossed in my head again! sniffing too much seafoam I think~

 

how much would this cost

 

make some calls- most shops will test it for free and then check whatexact cat you need and its price-
Other post on this thread have dealer and hi quality aftemarket price listed
Thats a starting point- if under 300 you are getting a deal

 

Dont know till you call. Location and every shop is different.