90_Straight6

Thanks for the clarification. I appreciate it. I did not know these did not have pre and post cat sensors. Makes sense now.

rikard

On a OBDI system removing the cat won't set a DTC. The O2 sensor is before the cat and its used to adjust the fuel air mixture. Even if you don't have to pass a sniff test you should keep the cat since federal law requires that the emission system remain intact. Many states don't check so people mistakenly think its legal to remove the emission components.
Be aware many states are getting tougher on checking for missing emission equipment. Even though my 95 is not smogged in Mass because its OBDI the inspector looks for "alterations" and a functioning CEL which is something that they didn't do two years ago. When I questioned him about what "alterations" he was checking he said anything that wasn't stock. My local custom exhaust shop confirmed that inspections were getting more stringent and any exhaust that doesn't exit in the stock location could be rejected. Since our inspections are done by repair shops some are easier than others to get through. Most state DMVs publish the their standards on line. I have argued and won a couple of times when I was able to quote chapter and verse when dealing with uninformed inspectors. ie My 82 Chevy DRW C 3500 didn't have cats because it was over the weight limit and it was going to flunk until I pointed out the 8600 lb limit. On another occasion the inspector didn't like my 94 Rc Sb F150 exhaust coming out the side before the rear tire until I pointed out a 97+ Rc Lb F250 that had the same exhaust configuration in his lot.
"Oh yeah that's my truck, Ok your all set"
I wasn't going to point out that the trucks were different generations and that Ford never offered the exhaust out the side before the rear wheel on my 94.
Know the laws especially when dealing with people who should know them.
YMMV
rikard

xredxfate

Wow, Thanks for the posts and help guys. I finalized it this morning and this is what I did. Flowmaster 40 1 in 2 out with 2.5in pipes. I did leave the cats on and i did recognize the O2 sensor before the cats. If i do pull them off and replace them with a single high-flow cat would I still pass CT emissions?



It sounds better than I expected and I am pleased with the results

mustangGT90210

More pictures PLEASE! Especially from under the truck, that's how I want to run my exhaust

Just call me Sean

iTrader: (1)

Yes it should pass with a single.

Ford 4x4

do you still have your cats on?

Welder7018

Nope. But I'm keeping mine in the shed just incase the state decides to do inspections. I just have a ypipe going to a 2 3/4 pipe then to my flowmaster 40

Welder7018

X2!!! And a video of how it sounds.

Ford 4x4

i see, i was thinking of going true duals with a flowmaster 40 on each pipe

Welder7018

Dual 40s sound kinda quiet almost stock quiet. I'd get a flowmaster 40 with single in dual out and go dual pipes like that.