i did catless dp because i needede the extra air flow for my big spooly boi. if you dont have an exhaust restriction, and you’re not modified its dumb. i had a high flow cat that was still restricting like 100hp worth of airflow so it made sense for me. as somebody who got a high flow cat i can confirm with air mass readings at the MAF before and after that no obstruction flows better than some obstruction.

hard analogy to make. biological systems are so different than mechanical.

the life blood of my car is my paycheck tho.

You under fill the tire you wanna wear out.

As long as your tuner does an 02 sensor delete you’re good. Just talk to your tuner to ensure they offer that. Are you planning the build with your tuner? If not I highly recommend leveraging them for support.

Prob head gasket. Can be repaired. Don’t drive it at all or start it coolant will prevent the oil from lubricating properly.

Did your own downpipe have two rear 02 sensors? If you plug em you gotta tell the ECM they aren’t there.

Nah I wouldn’t remove material that is structural.

Check your sleeves too to make sure they didn’t get beat up.