Check Engine Light on Due to Faulty Catalytic Conveter on Cadillac DeVille

Problem Description and Possible Solution

Failure of the catalytic converter can result in illumination of the Check Engine Light.

Problem Data
RepairPal Verified
Average mileage: 125,814 (65,000–220,000)
7 model years affected: 1991, 2000, 2001, 2002, more2003, 2004, 2005
50 people reported this problem
Viewing 1 - 15 of 15 comments
Check Engine Light on due to catalytic converter
code. used treatment with "seafoam" engine spray and lube $10 vs $300 after market converter or 1000 oem
Right after I bought the car the check engine light came on so I am not sure when it actually started. I bought it second hand. i have not fixed it.
Cat failure. Replaced Cat and less than 2 months later the Cat failed again
replaced catalytic converter a few days latter light came on again. replaced sensor, light came on again. mechanic said needs to be programed.
Codes p0420 and p0300 are coming up. Replacing catalytic converter. There is only one right? The p0300 came up 2x on dash.
need new catalytic converter
Check engine light came on and coded that it was an issue with the Catalytic Converter. Totally sucks.
Insalled Walker catalytic converter, $128.00 on Ebay. 6 weeks ago...still good
Catalytic converter wore out, replaced
I had light on CHECK ENGIN went to local Cadillac Dealer and was informed it was the CAT.Con. and I required a new one @ 3667.00 plus labour so I went to a well known muffler shop here in Kelowna,B.C. Canada and had a generic one installed for 350.00 inc. tax.labour and productand it runs just fine now / I was an un:suspecting buyer it had been a taxi in Culver city Ca. sold to a cab. in Nevada / and mills were rolled back to 50.000 miles/ I got all this info after I bought it from car fax ?? / I paid 7200.00 and spent about 3000.00 but it runs like a charm now / but get a used car checked befor you buy I never would have bought a used taxi/limo.
pipe burn red at the back of catalytic pipe
Engine keeps getting hot also check engine light is on. Changed. Water pump radiator hoses cap gasket sealant flush. Don't know what else to do
Ruff idle shinning sound vibration miss fire changed coil pack and spark plugs same problem persists
Just out of the 6 year / 100K certified warranty. It cost me over $1000.00 to repair. I was told this is because engine oil consumptiom burns them out.