In my state, which has an annual emissions inspection, I have yet to meet a non-dealer mechanic who will not do everything possible to get a vehicle with a bad cat through the inspection process.
They just want to get you on the road and they’re damn good about it (and to be fair much of what they do to pass actually fixes real issues - i went from being a gross polluter to passing when the mechanic replaced the spark plug wire that was grounding out).
>They just want to get you on the road and they’re damn good about it
Don't worry, the east coast has a solution for this harmonious alignment of business and customer incentives: 'safety' inspections
I took the training back when I lived in MA. The 3rd party that did the training (same contractor that did the computer systems at the time) basically said that the state's priority is clean air and that safety inspections only exist to make the combined safety+emissions license lucrative for a shop to hold and create an incentive not to subvert the interest of the state (by fudging emissions inspections) in favor of the customer (who the mechanic wants a good relationship with). Basically they want doing business via the state (by using your inspection license to make a bunch of work) to be more lucrative than any business you get helping customers dodge the state's interest. The lady running the training even started it by congratulating the class on "this lucrative next step in our careers and businesses" (which is somewhat hilarious because there is very little easy money in automotive repair).
That said, by the time I got out of that industry (mid 00s) they had stopped using tailpipe sniffers (at least in MA) and the economic realities of parts vs labor had more or less made any cheating beyond what the vehicle owner could do themselves irrelevant.
Last summer, I accompanied my son when he went across the state line to purchase a truck from a private seller. Said state has no inspection requirements. One of the seller's other trucks was a diesel conversion, and the exhaust was just routed up through the bonnet. Definitely no cat on that vehicle!
Nowadays the real emission inspection is the computer in the car itself, continually monitoring and tracking what is going on.
EGR valves -> DPFs -> DEF
I understand the necessity of these systems, but it seems like they are incredible fragile (the DPFs on VWs are prone to cracking and new ones are more than the average cat). I also understand why people do DPF deletes...