Now fellas my 05 ranger is a 3.0 v6 and I got 3 cats. 2 pre and a post cat I seem to have a clogging left bank pre cat and need to install a new one. Naturally I’m gonna. Do both and install a new exhaust system to help with performance and yeah a little sound. My question is can I delete the rear cat and run the two header cats or while I not pass smog? Cuz I wanted to do that sick dual exhaust! But yeah cuz I got a inconsistent rev and a hesitation when I press the gas if u guys got any ideas I would appreciate it and yeah I already did full air system checks replaces and cleaning and replaced fuel filter and a mechanic buddy showed me diagnostics that 4,5,6 on left bang have excess back pressure and said that’s causing the issue.

 

Welcome to the forum

In Calif. they check for the Cats, you won't pass if one is missing, you have probably seen them using that long handled mirror to look at the underside of a vehicle

And you won't pass emissions either because your Rear O2 sensor will set a code because of the missing Cat, and you can't even be tested with CEL(check engine light) on

 

well my trucks o2 sensors are at the pre cats. But I’m just gonna replace the entire exhaust system but what about the erratic idle and loss of rpms when getting up to speed it’s like a hesitation.

 

???

I thought the engine issues were diagnosed as clogged exhaust?

A V6 engine has 2 upstream O2 sensors, one on each bank/side before the Cats, these are used for fuel trims, then there would be a 3rd downstream O2 after the last Cat, or a 4th if it has Dual exhaust
The downstream O2 is used to test Cat converter operation, it will set a code, which will turn on CEL, if Oxygen level, at that O2 sensor, gets too high, i.e. Cat not working well