Ultima GTR ls7 engine 650hp

[BILLGTR]

Failed twice IVA test on emissions too high. Anyone have a cure for this. Noted emissions an issue with Ls7 engines

[rottenegg]

Fit the biggest cat(s) you get in there.

[Steve_D]

Not a lot of info to go on there Bill.
Would help if you told everyone the specifications such as what ECU are you running, if GM then what fault codes are present, as already mentioned what cats are fitted. In your email you mention big cam and big overlap both of which are red flags for emissions.

Steve