1999 Accord oil burning problem

My 99 Accord v6 with 45k miles burns 1+ quarts of oil every 1000 miles. Have had several rounds with the dealer to no avail despite extended warranty. Oil consumption test results of 1+ quarts are said to be "within tolerances" and therefore, not a warranty item. Now CHECK ENGINE light is on and mechanic has indicated it is the catalytic converter that is malfunctioning. Likely cause is oil clogging the unit. Accord barely passed CA smog test as well due to excessive hydrocarbon emissions. Has anyone had a similar problem with 1999 Accord v6s? Are these engines known to burn oil at this rate? Any ideas on what it might be? Seems ridiculous that car would burn through three quarts of oil between oil changes!

Thanks for any input.

It’s uncharacteristic for J30A1 engine. try another dealer.